Improve meal — or I eat nuts (10)
I believe the answer is:
ameliorate
'improve' is the definition.
(synonyms)
'meal or i eat nuts' is the wordplay.
'nuts' is an anagram indicator (nuts can mean crazy).
'meal'+'or'+'i'+'eat'='mealorieat'
'mealorieat' is an anagram of 'AMELIORATE'.
(Other definitions for ameliorate that I've seen before include "Become better" , "seen to improve" , "Make (something) better" , "Make (a bad thing) better" .)