Across
Used to celebrate Unionist politician standing by husband amid court case (9)
I haven't cracked this one yet — but Fifteensquared have:
U (abbreviation for Unionist) + MP (abbreviation for Member of Parliament = politician) + H (abbreviation for husband), all inside TRIAL (court case).
Idiot on Love Island enters safe space (5)
I haven't cracked this one yet — but Fifteensquared have:
ASS (idiot) added to O (zero = love in tennis scoring), with I (abbreviation for island) inserted (. . . enters). Oasis in the metaphorical sense: somewhere peaceful in the middle of a lot of stress and noise.
Considerable violence or hate (5)
I haven't cracked this one yet — but Fifteensquared have:
ABH (police abbreviation for “assault occasioning actual bodily harm” = a violent attack) + OR .
Where you might go for a drive by the coast? (4,5)
I haven't cracked this one yet — but Fifteensquared have:
Cryptic definition. Golf links = a golf course built on sandy coastland; drive = to hit a golf ball.
When key's missing, start boiling with rage (3-4)
I haven't cracked this one yet — but Fifteensquared have:
HOT (boiling) + W (abbreviation for with) + IRE (rage). Hot-wire = to start a car without the key, by connecting wires to bypass the ignition switch.
16d
(and 16 Down) At first, monitor out-of-control lorry going around nuclear plant (7,5)
In recession, group of countries protects energy employment (5)
I haven't cracked this one yet — but Fifteensquared have:
EU (abbreviation for European Union = group of countries) around (protecting) GAS (energy, as in “energy bill” = a bill for domestic gas and/or electricity), all reversed (in recession).
Occasionally stroke little piggy (3)
I haven't cracked this one yet — but Fifteensquared have:
Alternate letters (occasionally) of [s] T [r] O [k] E . As in the children’s rhyme “This little piggy went to market”, describing the five toes on a foot.
Show involving Post Office framing worker (5)
Jaguar takes on firm that's adapted to the local environment (7)
I haven't cracked this one yet — but Fifteensquared have:
E-TYPE (model of car made by Jaguar), containing (. . . takes on) CO (abbreviation for company = firm). A group of organisms within a species that is adapted to the environment in a particular location, and therefore slightly different from the same species elsewhere.
O'Sullivan's third trick shot enthrals the UK, for one (7)
I haven't cracked this one yet — but Fifteensquared have:
Third letter of [os] U [llivan], contained in (. . . enthrals) CON (trick = deception) + TRY (shot = an attempt, as in “give it a shot”). The surface appears to refer to the snooker player Ronnie O’Sullivan.
In lab coat, breaking down plant-based substance (9)
Quickly make approach (3-2)
I haven't cracked this one yet — but Fifteensquared have:
RUN UP (make quickly, especially as in a dressmaker creating a garment at short notice). Not quite a double definition because this usage doesn’t include a hyphen. Definition as in “the run-up to the big match” = the days or hours immediately preceding it.
They deliver extremely extravagant surprise (5)
I haven't cracked this one yet — but Fifteensquared have:
UPS (a US delivery company = they deliver) + end letters (extremes) of E [xtravagan] T . Perhaps in the sporting sense of “upset” = when a good competitor/team is beaten by one thought to be inferior.
Latin poet's wasted promise (9)
I haven't cracked this one yet — but Fifteensquared have:
Anagram (wasted = drunk or destroyed) of LATIN POET . In the sense of “shows promise” or “shows potential” = could become much better.
Down
Separatists no longer controlling northern Italian mountain (4)
I haven't cracked this one yet — but Fifteensquared have:
ETA (Basque separatist group, formally disbanded in 2018, hence “no longer”), containing (controlling) N (abbreviation for northern). Volcanic mountain in Sicily, Italy.
Fashionable group of ladies welcome to visit every other part of state (4-2)
I haven't cracked this one yet — but Fifteensquared have:
WI (abbreviation for Women’s Institute = group of ladies), then HI (hi! = welcome! = a greeting) inside (to visit) every other letter of [s] T [a] T [e].
Weirdly morbid, eery decoration (10)
23d
(and 23 Down) Film gets a cheer, unexpectedly breaking record (3,5,6)
Perhaps Flanders is hosting a climbing event (6)
I haven't cracked this one yet — but Fifteensquared have:
MOLL’S (perhaps Moll Flanders, from the Daniel Defoe novel, and possessive ‘s = is), containing (hosting) A , all reversed (climbing = upwards in a down clue). Winter sports event.
Smooth part of speech (4)
I haven't cracked this one yet — but Fifteensquared have:
Sound-alike (. . . of speech) of ROLE = a part in a play. For example, to smooth (flatten) a lawn by the use of a heavy roller.
Capital cousin misguidedly invested in decentralised altcoin (8)
I haven't cracked this one yet — but Fifteensquared have:
Anagram (misguidedly) of COUSIN , inside A [ltcoi] N with the centre letters removed (de-centralised?). Capital city of Paraguay.
Cold-blooded killers slip away, quietly heading south (4)
I haven't cracked this one yet — but Fifteensquared have:
PASS (slip away), with the P (p = abbreviation for Italian piano = musical term for quietly) moving towards the end of the word (south, in a down clue). Venomous snakes, which are cold-blooded creatures.
Jubilant cry heard at Mecca? (5)
I haven't cracked this one yet — but Fifteensquared have:
Cryptic definition: Mecca here is not the Islamic holy city, but a British company that runs bingo clubs, where a player may shout “house!” to indicate a win.
After temperature drops, expedition in danger amid the waves (3,7)
I haven't cracked this one yet — but Fifteensquared have:
[t] RIP (expedition) without the T (abbreviation for temperature), then CURRENT (in = popular). A fast-flowing offshore current among breaking waves on a beach, which is a dangerous thing to get caught in.
See 14 Across
Write off American, increasingly injecting this out of hospital (8)
I haven't cracked this one yet — but Fifteensquared have:
A (abbreviation for American), then MORE (increasingly) containing (injecting) T [h] IS without the H (abbreviation for hospital). In accounting terms, to write off the value of a depreciating asset over a number of years.
Rise in intensity irritated unmarried actor Paul earlier on (8)
I haven't cracked this one yet — but Fifteensquared have:
ATE (irritated, as in “what’s eating you?”), with [m] ESCAL (Irish actor Paul Mescal) at the start, without the M (abbreviation for married, hence dropping it = unmarried).
See 4 Down
Ready to ring pub about game (6)
I haven't cracked this one yet — but Fifteensquared have:
SET (ready) around (to ring = to surround) INN (pub = drinking establishment), all reversed (about).
Band's unexpected statement cut short (4)
I haven't cracked this one yet — but Fifteensquared have:
BLUR [t] (as a noun = an abupt outburst = unexpected statement: Chambers says this noun form is “rare” but it’s more common as a verb), without the last letter (cut short). Britpop band, formed in 1988.
Do for one finally taken to expert coiffeuse (4)
Go to bed with jerk (4)
I haven't cracked this one yet — but Fifteensquared have:
Double definition. Pull = slang for “to seduce successfully”; or jerk = to pull abruptly.
Type letters or click words in the clue