Across
Monarch unattended by day is wise man (4,7)
American pension manager ignoring call for attention in studio (7)
18d
Drunk legal stood down, getting prohibition notice (4,3,7)
Angry worker grabs one item of food (9)
I haven't cracked this one yet — but Fifteensquared have:
CROSS="Angry" + ANT="worker", around I="one"
Copied one that’s entering on foot (1,4)
I haven't cracked this one yet — but Fifteensquared have:
definition: à pied, French for "on foot" APED="copied" with I="one" entering inside
Tops of yew and fir’s fibrous bark (found in the Highlands) (4)
I haven't cracked this one yet — but Fifteensquared have:
definition: a Scottish word for to bark, to yelp top/first letters of Y-[aff] A-[nd] F-[ir's] F-[ibrous]
Perhaps Thatcher’s advice and negative comment given socialist spin (2,4,4)
Female’s rude shout and short cry after foreign article’s not bold enough (10)
Reviewed a great deal. (4)
Muddy son? For a bachelor, quite wet (5)
I haven't cracked this one yet — but Fifteensquared have:
B -OGGY="Muddy", with S for "son" replacing B for "bachelor"
Rising calls coming from stadiums (9)
Charm offensive finally by Belgian city – over investment (7)
I haven't cracked this one yet — but Fifteensquared have:
final letter of [offensiv]-E + NAMUR=name of a "Belgium city"; with O ("over", cricket abbreviation) invested inside
US approval for exit perhaps (3,2,2)
Mathematician and doctor at first easily selects second gear (6,5)
I haven't cracked this one yet — but Fifteensquared have:
definition: "gear" meaning clothing / an outfit SUMMER=someone who does sums="Mathematician" + DR (doctor) + "first" letters from E-[asily] S-[elects] S-[econd]
Down
Working Greek hopes staff refrain from using drugs? (4,3,3,5)
Identifies pins (5)
Hospital admits mistake over type of ham (7)
I haven't cracked this one yet — but Fifteensquared have:
SAN (sanatorium, "hospital"); around/admitting ERR="mistake" + O ("over", cricket abbreviation)
Lively young woman’s coffee-drinking diet regularly used (7)
I haven't cracked this one yet — but Fifteensquared have:
LATTE="coffee" taking in ("drinking"): regular letters from D-[i]-E-[t]
Fighters shouting, interrupting travellers (8)
Unions alone must become reformed, but not at the same time (15)
I haven't cracked this one yet — but Fifteensquared have:
anagram/"reformed" of (Unions alone must)*
Why courts tape abuse – be careful! (5,4,4)
I haven't cracked this one yet — but Fifteensquared have:
anagram/"abuse" of (Why courts tape)*
Trainee clergyman doesn’t start up collection (7,6)
I haven't cracked this one yet — but Fifteensquared have:
anagram/"collection" of (doesn't start up)* "collection" indicating the anagram: 'collect' is close in meaning to e.g. 'assemble', 'combine'
Pest from Division welcoming short surprise announcement (4,4)
I haven't cracked this one yet — but Fifteensquared have:
definition: a type of insect that acts as a pest [wiki] ARM [of e.g. a company]="Division"; around MY WOR-[d]=an announcement of surprise, short of its last letter
Kite’s treasurer (European) loses annual return and pay (7)
I haven't cracked this one yet — but Fifteensquared have:
I'M='I am'='Kite, the setter of this puzzle, is'="Kite's" + BURS-[ ar ]="treasurer" + E (European); minus ar for " a nnual r eturn"
See 10 Across
Frost narrated a piece of poetry (5)
Type letters or click words in the clue