Butt exposed around midnight (5)
I believe the answer is:
nudge
'butt' is the definition.
(thesaurus)
'exposed around midnight' is the wordplay.
'exposed' becomes 'nude' (I've seen this before).
'around' means one lot of letters goes inside another.
'midnight' becomes 'g' (the middle letter in 'night').
'nude' placed around 'g' is 'NUDGE'.
(Other definitions for nudge that I've seen before include "Jostle" , "Light touch or push" , "Poke gently with elbow" , "Gently encourage" , "Elbow someone gently" .)