Crunch unidentified object in drink (3-2)
I believe the answer is:
sit-up
'crunch' is the definition.
(I've seen this before)
'unidentified object in drink' is the wordplay.
'unidentified object' becomes 'it' (pronoun for an inanimate object. I am not sure about the 'unidentified' bit.).
'in' means one lot of letters goes inside another.
'drink' becomes 'sup' (to sup is to drink).
'it' going within 'sup' is 'SIT-UP'.
Can you help me to learn more?
(Other definitions for sit-up that I've seen before include "Exercise done on the floor" , "Physical exercise" , "Exercise designed to strengthen stomach muscles" .)