Giant, raving, hit a log (7)
I believe the answer is:
goliath
'giant' is the definition.
('goliath' can be a synonym of 'giant')
'raving hit a log' is the wordplay.
'raving' indicates an anagram.
'hit'+'a'+'log'='hitalog'
'hitalog' is an anagram of 'GOLIATH'.
(Other definitions for goliath that I've seen before include "David laid him low with slingshot" , "Giant Philistine laid low by David" , "Biblical giant" , "David slew him with a slingshot (7)" , "I got Hal a giant form the bible" .)