One man's name for a missile (3)
I believe the answer is:
sam
This clue is a triple definition!
'one man's' is the first definition.
(man's name)
'name' is the second definition.
'for a' acts as a link.
'missile' is the third definition.
(abbreviation for surface-to-air missile)
(Other definitions for sam that I've seen before include "Boy" , "Casablanca piano player" , "together once" , "Uncle" .)