Count abandoned model friend (4)
I believe the answer is:
ally
'friend' is the definition.
(an ally is a friend or supporter)
'count abandoned model' is the wordplay.
'count' becomes 'tally' (tallying is a kind of counting).
'abandoned' suggests deleting specific letters.
'model' becomes 't' (Ford Model T car).
'tally' with 't' taken out is 'ALLY'.
(Other definitions for ally that I've seen before include "Join - friend" , "Friend, partner" , "Colleague, confederate" , "Co-operating person or nation" , "Supporter in a conflict" .)