One splitting bananas daily (4)
I believe the answer is:
maid
'daily' is the definition.
(thesaurus)
'one splitting bananas' is the wordplay.
'one' becomes 'i' (Roman numeral).
'splitting' is an insertion indicator (some letters split a word into two).
'bananas' becomes 'mad' (slang for insane).
'i' going into 'mad' is 'MAID'.
(Other definitions for maid that I've seen before include "Female domestic servant" , "Female servant - young girl" , "One in service" , "- - -of-all-work" , "employee" .)