Devoured more than seven, say (3)
I believe the answer is:
'devoured' is the definition.
(I've seen this in other clues)
'more than seven say' is the wordplay.
'more than seven' becomes 'eight'.
'say' indicates a 'sounds like' (homophone) clue.
'eight' is a homophone of 'ATE'.
(Other definitions for ate that I've seen before include "Devoured" , "Tea (anag.)" , "Ingested" , "Consumed food" , "Took food" .)