"Pierce" is a man's name (5)
I believe the answer is:
lance
'pierce' is the definition.
(I know that lance is a type of pierce)
'a man's name' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for lance that I've seen before include "Long-shafted weapon" , "Surgical knife" , "Long pointed weapon of old" , "Incise" , "Horseman's long weapon" .)