Eat before appointment (7)
I believe the answer is:
predate
'eat' is the definition.
(I know that predate is a more specific form of the action forage)
'before appointment' is the wordplay.
'before' becomes 'pre' (prefix meaning 'before').
'appointment' becomes 'date' (synonyms).
'pre'+'date'='PREDATE'
(Other definitions for predate that I've seen before include "Be earlier in time" , "Go before" , "Track down and feed off" .)