Count on fellow getting work (4)
I believe the answer is:
hope
'count on' is the definition.
(thesaurus)
'fellow getting work' is the wordplay.
'fellow' becomes 'he' ('he' refers to a man).
'getting' indicates putting letters inside.
'work' becomes 'op' (abbreviation for opus).
'he' going around 'op' is 'HOPE'.
(Other definitions for hope that I've seen before include "Trust" , "One who wrote about prisoner" , "Expect and wish" , "confidence" , "combination of expectation and desire" .)