Eager boy finally in paid work (8)
I believe the answer is:
yearning
'eager' is the definition.
(thesaurus)
'boy finally in paid work' is the wordplay.
'finally' indicates one should take the final letters.
'in paid work' becomes 'earning' (I can't justify this - if you can you should believe this answer much more).
The final letter of 'boy' is 'y'.
'y'+'earning'='YEARNING'
Can you help me to learn more?
(Other definitions for yearning that I've seen before include "Hunger" , "Unfulfilled desire or need" , "Hankering, longing" , "Longing (for something)" , "Craving" .)