Turn a child against a certain vegetable (7)
I believe the answer is:
spinach
'certain vegetable' is the definition.
'spinach' can be an answer for 'vegetable' (spinach is a kind of vegetable). I'm not sure about the 'certain' bit.
'turn a child against a' is the wordplay.
'turn' becomes 'spin' (spin is a kind of turn).
'a child' becomes 'ch' (abbreviation for child).
'against' means one lot of letters go next to another.
'ch' put after 'a' is 'ach'.
'spin'+'ach'='SPINACH'
Can you help me to learn more?
(Other definitions for spinach that I've seen before include "Vegetable, source of iron" , "Popeye the Sailor's vegetable of choice" , "food" , "Vegetable leaves" , "Popeye the Sailor's favourite vegetable" .)