At least a dozen answer, giving endorsement (4)
I believe the answer is:
visa
'endorsement' is the definition.
(I know that visa is a type of endorsement)
'at least a dozen answer' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
The remaining letters 'vis' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'giving' is the link.
Can you help me to learn more?
(Other definitions for visa that I've seen before include "Travel pass" , "Travel document is required to enter Virginia" , "travel authority" , "Mark on passport" , "ID" .)