A man of conviction (3)
I believe the answer is:
lag
This clue might be a double definition.
'a man' is the first definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'conviction' is the second definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'of' is the link.
Can you help me to learn more?
(Other definitions for lag that I've seen before include "Convict (slang)" , "Old convict - dally - insulate" , "Get behind; convict" , "Insulate (pipes)" , "Fall behind with gal" .)