Across
Hit it off with American poet and Irish mathematician (8)
I haven't cracked this one yet — but Fifteensquared have:
HIT less IT + A[merican] + MILTON. William Rowan Hamilton was an Irish methematician who made contributions to abstract algebra and mechanics, and invented the Quaternions
The end of time, a brief moment recalled (5)
I haven't cracked this one yet — but Fifteensquared have:
Reverse of AGE + MO
Initially acceptable, telling inappropriate jokes finally grows old (4)
I haven't cracked this one yet — but Fifteensquared have:
First letter of Acceptable + the last letters of tellinG inappropriatE jokeS
Locals digest a bishop’s stories (10)
I haven't cracked this one yet — but Fifteensquared have:
A RR (Right Reverend, style of a bishop) in NATIVES
Marks, Jos and Russells? (6)
I haven't cracked this one yet — but Fifteensquared have:
Double (or triple) definitions: marks as in branding cattle, and Jo and Russell as examples of people with the surname Brand (Jo is a comedian, and I prefer not to have to think about Russell)
PM once lost face with 9th pregnancy and little ones here? (8)
I haven't cracked this one yet — but Fifteensquared have:
[t]HATCHER + the 9th letter of pregnancY
Recipe for making unique lunch with asparagus tips (7)
Meadow’s fine mature greenery (7)
Cyclist’s lady exchanging ring for stiletto? (8)
I haven't cracked this one yet — but Fifteensquared have:
WOMAN replacing O (ring) with HEEL
Trade item again, instrument not about to be put in tin (4,2)
I haven't cracked this one yet — but Fifteensquared have:
CELLO less C (circa, about) in SN (tin)
Bill confused with A-minus being hidden (10)
Chase knight into building (4)
Knocks doors electioneering – Nigel trails, Starmer leads (5)
I haven't cracked this one yet — but Fifteensquared have:
More first letters: Doors Electioneering Nigel Trails Starmer
Coincides with cryptic solver tackling advanced puzzle to begin with (8)
I haven't cracked this one yet — but Fifteensquared have:
And more: Advanced Puzzle in SOLVER*
Down
Australian with organ failure stops climbing tree (8)
Spit out fruit 3 (4)
During the weekend, tense individual rocks (6)
I haven't cracked this one yet — but Fifteensquared have:
T[ense] ONE in S[aturday] S[unday]
Following acting in New York, Sly brings chaos (7)
I haven't cracked this one yet — but Fifteensquared have:
A (acting) + ARCH (sly) in NY
In Boston, pop old penny into it (4)
I haven't cracked this one yet — but Fifteensquared have:
O (old) D (symbol for the old penny) in SA (Sex Appeal, “it”)
500 + (8 ÷ 50) + 4? Oddly, 50 is great (10)
I haven't cracked this one yet — but Fifteensquared have:
D (500) + L (50) in (dividing) EIGHT + odd letters of FoUr + L (50 again)
Progress through life in a rush (6)
Capital supports miners close to strike 1, 2, 3 and more (6,4)
Bond releasing his boss from period in jail (3)
I haven't cracked this one yet — but Fifteensquared have:
TIME (jail sentence) less M (James Bond’s boss)
Upset gentleman dropping tablet for hit (3)
I haven't cracked this one yet — but Fifteensquared have:
Reverse of MALE less E (ecstasy tablet)
Adults in gangs steal women’s clothing (5-3)
I haven't cracked this one yet — but Fifteensquared have:
W[omen]S in GROUPS
Evenly tanned pair of legs outside without end (2,3,2)
I haven't cracked this one yet — but Fifteensquared have:
Even letters of tAnNeD between two instances of ON (the leg side in cricket)
Chases 1,000s, blowing top as criminal escapes (6)
I haven't cracked this one yet — but Fifteensquared have:
THOUSANDS less its first letter and AS*
Lithium twisted inside small piece of metal (6)
I haven't cracked this one yet — but Fifteensquared have:
SLIVER (small piece) with LI “twsted”
Three seconds’ growth (4)
I haven't cracked this one yet — but Fifteensquared have:
MO (moment) + S S
Rise and relax, free of cold (4)
I haven't cracked this one yet — but Fifteensquared have:
CHILL less C
Type letters or click words in the clue