Intentions of excellent modern miss (4)
I believe the answer is:
aims
'intentions' is the definition.
('aim' can be a synonym of 'intention')
'excellent modern miss' is the wordplay.
'excellent' becomes 'ai'.
'modern miss' becomes 'ms' (alternative to 'miss').
'ai'+'ms'='AIMS'
'of' acts as a link.
(Other definitions for aims that I've seen before include "Purposes or intentions" , "Sets sight on, having ambitions" , "Trains - intentions" , "Objectives, purposes" , "Points a weapon" .)