Work out alone around five (5)
I believe the answer is:
solve
'work out' is the definition.
(thesaurus)
'alone around five' is the wordplay.
'alone' becomes 'sole' ('sole' can be a synonym of 'alone').
'around' is an insertion indicator.
'five' becomes 'v' (roman numeral).
'sole' enclosing 'v' is 'SOLVE'.
(Other definitions for solve that I've seen before include "Find the answer to a mystery" , "Figure out the answer" , "Find the answer to a puzzle" , "Find the key - work out" , "Unravel (a problem)" .)