With opening try, man’s totally committed (12)
I believe the answer is:
wholehearted
'committed' is the definition.
(thesaurus)
'with opening try man's totally' is the wordplay.
'with' becomes 'w' (short for with).
'opening' becomes 'hole' (hole is a kind of opening).
'try man's totally' becomes 'hearted' (I can't explain this - if you can you should believe this answer much more).
'w'+'hole'+'hearted'='WHOLEHEARTED'
Can you help me to learn more?
(Other definitions for wholehearted that I've seen before include "Completely sincere and committed" , "Unqualified" , "Zealous and sincere" , "Unreserved - affectionate" , "With enthusiastic devotion" .)