It means something when you write a name (6)
I believe the answer is:
signal
'it means something when' is the definition.
The definition suggests a singular noun which matches the answer.
'write a name' is the wordplay.
'write' becomes 'sign' (signing is a kind of writing).
'a name' becomes 'Al'.
'sign'+'al'='SIGNAL'
'you' is the link.
Can you help me to learn more?
(Other definitions for signal that I've seen before include "Message in the form of a gesture" , "Important; gesture" , "Noteworthy" , "(Traffic) light" , "(Railway) indicator" .)