Every adult caught in what? (4)
I believe the answer is:
each
'every' is the definition.
(synonyms)
'adult caught in what?' is the wordplay.
'adult' becomes 'a' (abbreviation).
'caught' becomes 'c' (cricket abbreviation).
'in' means one lot of letters goes inside another.
'what?' becomes 'eh' (I've seen this in another clue).
'a'+'c'='ac'
'ac' placed within 'eh' is 'EACH'.
(Other definitions for each that I've seen before include "...per head" , "Ache (anag.)" , "every individual" , "Singly, per capita" , "Every - apiece" .)