Aim to anger snake first (6)
I believe the answer is:
aspire
'aim' is the definition.
(synonyms)
'anger snake first' is the wordplay.
'anger' becomes 'ire' (ire is intense rage).
'snake' becomes 'asp' (asp is a kind of snake).
'first' is a charade indicator (letters next to each other).
'ire' after 'asp' is 'ASPIRE'.
'to' is the link.
(Other definitions for aspire that I've seen before include "Have ambition (to achieve something)" , "Have lofty aims" , "Have an ambitious plan or a lofty goal" , "Aim, shoot for" , "Have ambitions (to achieve something)" .)