Keenly very into daily working (6)
I believe the answer is:
avidly
'keenly' is the definition.
(I've seen this before)
'very into daily working' is the wordplay.
'very' becomes 'v' (abbreviation).
'into' indicates putting letters inside.
'working' indicates an anagram.
'daily' is an anagram of 'aidly'.
'v' going inside 'aidly' is 'AVIDLY'.
(Other definitions for avidly that I've seen before include "In enthusiastic manner" , "Eagerly, maybe greedily" , "With eagerness" , "with enthusiasm" , "Keenly, eagerly" .)