Year in company great on the whole (2,3,5)
I believe the answer is:
by and large
'on the whole' is the definition.
(both can mean 'generally')
'year in company great' is the wordplay.
I cannot really see how this works, but
'year' could be 'y' and 'y' is found within the answer.
'company' could be 'band' (I've seen this in another clue) and 'band' is present in the remaining letters.
'great' could be 'large' (synonyms) and 'large' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for by and large that I've seen before include "In general" , "As a rule" , "Speaking generally" , "In the main" , "for the most part" .)