Caught getting into booze, flinch (5)
I believe the answer is:
wince
'flinch' is the definition.
(I know that flinch can be written as wince)
'caught getting into booze' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'getting into' means one lot of letters goes inside another.
'booze' becomes 'wine' (wining is a kind of boozing).
'c' inserted into 'wine' is 'WINCE'.
(Other definitions for wince that I've seen before include "Flinch with pain" , "pained" , "Recoil with pain" , "show embarrassment" , "Make face showing pain" .)