Thank you to Turnstone. Definitions are underlined in the clues.
Across
1. Countryside walkers go on grass regularly (8)
RAMBLERS : RAMBLE(talk extensively/go on) + 2nd and 4th letters of(… regularly) “grass”.

6. Physical training on esplanade is timely (6)
PROMPT : PT(abbrev. for “physical training”) placed after(on) PROM(short for “promenade”, in a seaside town, a road by the sea for people to go walking/an esplanade)
9. Origin of flexible course (6)
SOURCE : Anagram of(flexible) COURSE.
10. Force translation of Cicero? No! (8)
COERCION : Anagram of(translation of) CICERO? NO.
Defn: … used to gain compliance.
11. Travelling miles to north-eastern rock (9)
LIMESTONE : Anagram of(Travelling) MILES + TO + NE(abbrev. for “north-eastern”).
Defn: A sedimentary ….
13. Seven ushers surrounding goddess (5)
VENUS : Hidden in(… surrounding) “Seven ushers”.
15. Very sad ending to Hamlet leads to riots against Gertrude in consequence (6)
TRAGIC : Last letter of(ending to) “Hamlet” + 1st letters, respectively, of(leads to) “riots against Gertrude in consequence”.
17. Paris art revolution absorbs philosopher (6)
SARTRE : Hidden in(… absorbs) “Paris art revolution”.
Answer: Jean-Paul …, French philosopher.
18. Withdraw from drive back across Australia (6)
REPEAL : REPEL(to force something away/to drive back) containing(across) A(abbrev. for “Australia”).
Defn: To cancel, say, a law.
19. Dish overwhelms a sense of taste (6)
PALATE : PLATE(a flat shallow dish) containing(overwhelms) A.
Defn: …/one’s ability to experience and appreciate flavours.
21. Oscar frequently clutches muffler (5)
SCARF : Hidden in(… clutches) “Oscar frequently”.
22. Incentives to buy liberal Guardian at first, then Independent, FT and Sun (4,5)
FREE GIFTS : FREE(liberal/unrestricted) + 1st letter of(… at first) “Guardian” plus(then) I(abbrev. for “Independent”) + FT + S(abbrev. for “sun”?).
Answer: … that come with your purchase.
25. Reserve placing first in tango? (8)
DISTANCE : IST(“1st”/abbrev. for “first”, with the Roman numeral substitution) contained in(placing … in) DANCE(an example of which/? is the tango).
Defn: …/a lack of involvement with someone.
26. Produce unlawful broadcast roughly (6)
ELICIT : Homophone of(… broadcast roughly) “illicit”(unlawful).
28. Complete agreement from academic offspring? (6)
UNISON : [UNI-SON](how you might describe the offspring/son of one who is an academic in a university).
29. Sadly, not big in home-improvement (8)
DISMALLY : SMALL(not big) contained in(in) DIY(abbrev. for “do-it-yourself”, the practice of doing on your own the job of, say, modifying or decorating/improving your home).
Down
2. Principles of Ancient Greece overthrown in the past (3)
AGO : 1st letters, respectively, of(Principles of) “Ancient Greece overthrown”.
3. Move clumsily in boat (5)
BARGE : Double defn.
4. Celtic and Real played with a kind of energy (10)
ELECTRICAL : Anagram of(… played with) [CELTIC plus(and) REAL].
5. Back in a mo! (6)
SECOND : Double defn: 1st: To support, say, a proposal.
6. Reportedly look for breakwater (4)
PIER : Homophone of(Reportedly) “peer”(to look very hard at something).
7. Gold box right next to a group of musicians (9)
ORCHESTRA : OR(gold colour in heraldry) + CHEST(a large heavy box) + R(abbrev. for “right”) plus(next to) A.
8. Acquisition of professional remedy meant amateur excluded (11)
PROCUREMENT : PRO(short for “professional”) + CURE(remedy/treatment to rectify a sickness or problem) + “meant” minus(… excluded) “a”(abbrev. for “amateur”).
12. Ancient trio improvised joint performance (11)
INTERACTION : Anagram of(… improvised) ANCIENT TRIO.
14. Badly parse a term for boundaries (10)
PARAMETERS : Anagram of(Badly) PARSE A TERM.
Defn: … limiting the way something can be done or made.
16. Astronauts initially strap up a complicated piece of equipment (9)
APPARATUS : 1st letter of(… initially) “Astronauts” + anagram of(… complicated) STRAP UP A.
20. Mate cooked around noon (6)
FRIEND : FRIED(of food, cooked in hot oil or fat) containing(around) N(abbrev. for “noon”).
23. Current business account’s opening in island (5)
IBIZA : I(symbol for electric current in physics) + BIZ(informal term for “business”) + 1st letter of(…’s opening) “account”.
Answer: A Spanish island in the Mediterranean Sea.
24. Member of clergy loses hat immediately according to Shakespeare (4)
ANON : “canon”(a Christian priest, member of the clergy) minus(loses) its 1st letter(hat/top letter, in a down clue).
Answer: …, in poetic language found in classical literature such as the works of Shakespeare.
27. Unwell? Unwrap tablets (3)
ILL : “pills”(tablets of medicine) minus its 1st and last letters(Unwrap …).
Thanks Turnstone and scchua
Is Turnstone new? I don’t recall coming across this compiler before.
I loved the neat anagram for ELECTRICAL.
Edit: a search reveals several previous puzzles by Turnstone, one of which I even commented on!
With reference to 2 down, would the first letters of a phrase not be its ‘principals’, rather than its ‘principles’? Or is someone going to tell me that the semantic distinction, like that between ‘therefore’ and ‘thus’ the other day, has been eroded through persistent misuse and is now enshrined in dictionaries?
First letters are arguably principals, not principles, but I guess all’s fair in love and cryptics?
Good fun — nice to have no obscurities.
Done before I had finished my coffee. So either I am getting better at crosswords or more likely, this was at the easier end of the scale ?
muffin @1 – Turnstone has set a couple of Quick Cryptics #101 and #114, and I’m pretty sure, a Quiptic or too.
Fun puzzle.
Thank you to Turnstone and scchua
Very nice, especially TRAGIC and FREE GIFTS but lots of ticks.
Ta Turnstone & scchua
Enjoyed this. Quite gentle, very smooth clues and surfaces which were right in the Quiptic sweet spot IMO. Thanks Turnstone, and Scchua.
When I did a search, I saw that Turnstone has done a few Quiptics and a Genius
Balfour@2 – “has been eroded through persistent misuse and is now enshrined in dictionaries”. For almost a thousand years! Words change their meanings. Hence: cryptic crosswords.
Balfour@2: I too would have preferred ‘principals’. I saw this in another crossword recently (can’t remember which) and wondered at the time whether the setter’s choice was deliberate or inadvertent. OED’s first definition of ‘principle’, with citations from 1382, is “That from which something originates or is derived; a source, an origin; the root (of a word, etc)”. Citations for ‘principal’ also date from the 14th century. I’m not really taking issue with you here; merely wondering whether there was much semantic distinction in the first place.
Conrad @9 So you are quite OK with the current erosion of the distinction between ‘uninterested’ and ‘disinterested’ because enough users don’t understand the difference? I’m not.
[Balfour @11, personally I prefer the distinction, but the word has meant ‘uninterested’ at least as long as it has meant ‘impartial’; the OED cites John Donne and Jeremy Taylor, one of the most respected prose stylists of the seventeenth century. I silently dislike it when people use ‘deprecate’ to mean ‘depreciate’, or ‘discomfit’ to mean ‘discomfort’, but I would never dream of being vocally pedantic on the matter. What’s the point? It is just objectively a fallacy to think that such shifts indicate some newfound sloppiness in the world (“current erosion”), and after a while, misuse becomes simply use. To deny that isn’t pedantry; it is an inability to understand that language is, and always will be, fluid. It’s arbitrary to complain about thus/therefore and not about the million other shifts that make cryptics delightfully possible.]
A perfect Quiptic this morning. No problem with principle, meaning “source, root or origin”. Thanks Turnstone and Scchua
Nice and straightforward, as a Quiptic should be. Thanks both.
AGO
Collins has this entry under principle
a source or fundamental cause; origin
principle of life
(adding to what HumbleTim said)
I love the way crosswords teach me things. Eg I symbol for electric current in physics. Really enjoyed this one and didn’t need too much fifteen squared although I still like to check. Thanks both.
First tried to do it in the middle of the night but apparently my brain just was too sleepy, and I couldn’t do anything; in the morning all went in well. There are some very nice anagrams and hidden words here; also, some great finds like GIFTS, UNISON and the surface of SECOND. Thanks Turnstone and scchua!
Nicely pitched. A very pleasant distraction from Sunday chores.
Thank you Turnstone & scchua.
Lovely quiptic! Thank you Turnstone and scchua.
I also had misgivings about “principle” but our bible Chambers gives the definition “3. A beginning (obsolete)”. So for a crossword clue I have no complaint, although would groan to see it in a Guardian column 🙂
So perhaps “principle” NOT meaning “A beginning (obsolete)” is in fact the sloppy degenerate modern version? I must admit that some of these changes do make me wince (I get quite annoyed with the persistent “shoe-in” for an uncontested election) but I hadn’t noticed that one, and none of them are hills worth dying on.
Anyway, thanks to Turnstone for a simple but stylish Quiptic: I liked the TRAGIC goings-on at Elsinore, but my favourite was “Back in a mo!”
There seems little consensus about these matters, but I shall continue, in my own speaking and writing, NOT to use ‘thus’ when I mean ‘therefore’, NOT to use ‘disinterested’ when I mean ‘uninterested’, NOT to use ‘principle’ when I mean ‘principal’ and to maintain the syntactical distinction between ‘who’ and ‘whom’. which appears to be vanishing even in seemingly ‘educated’ writing.
[A BBC report online earlier today referred to “the epicentre of the Spanish fires”.]
[This is it:
‘This landscape is completely charred’: Inside the village at epicentre of Spain’s wildfires’]
Many thanks to Turnstone and scchua. I thought this was an excellent Quiptic, fundamentally doable with just enough tricky corners to give me pause. I especially liked IBIZA, ELICIT and DISMALLY. Great stuff.
Defining PARAMETERS as “boundaries” (14dn) irritates me in the same way as the principle / principal problem does others. In my world, a parameter is an adjustable quantity that affects other quantities, not a boundary. But the dictionaries recognize the other usage, so I just have to live with it.
Is really “drive away” the same as “drive back”???