A name I had for being convincing (5)
I believe the answer is:
valid
'being convincing' is the definition.
(thesaurus)
'a name i had' is the wordplay.
'a name' becomes 'val' (**).
'i had' becomes 'id' (I'd).
'val'+'id'='VALID'
'for' is the link.
(Other definitions for valid that I've seen before include "Binding" , "Reasonable" , "Legally acceptable, unexpired" , "Officially acceptable" , "Based on reason or law" .)