Question about English dairy product? (4)
I believe the answer is:
'dairy product' is the definition.
(whey is a kind of dairy product)
'question about english' is the wordplay.
'question' becomes 'why' (I've seen this in other clues).
'about' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'why' going around 'e' is 'WHEY'.
(Other definitions for whey that I've seen before include "Residual liquid from clotted milk" , "Watery part of milk after curd separation" , "Watery content of milk" , "Watery residue of milk" , "Watery dairy product" .)