Dad’s pin-up eating top of raw vegetable (7)
I believe the answer is:
parsnip
'vegetable' is the definition.
(parsnip is a kind of vegetable)
'dad's pin-up eating top of raw' is the wordplay.
'dad's' becomes 'pas' ('pa' can be a synonym of 'dad'**).
'up' is a reversal indicator (in down clue: letters go upwards).
'eating' indicates putting letters inside.
'top of' says to take the initial letters.
The first letter of 'raw' is 'r'.
'pin' backwards is 'nip'.
'pas'+'nip'='pasnip'
'pasnip' going around 'r' is 'PARSNIP'.
(Other definitions for parsnip that I've seen before include "Yellow root vegetable" , "Sweet root vegetable" , "Plant with edible white root" , "A white root vegetable" , "food" .)