Skinny model has the edge (4)
I believe the answer is:
trim
'edge' is the definition.
(I've seen this in another clue)
'skinny model has the' is the wordplay.
'skinny model' becomes 'rim' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'has' says to put letters next to each other.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'rim' after 't' is 'TRIM'.
Can you help me to learn more?
(Other definitions for trim that I've seen before include "Pare; an ornament" , "Shorten" , "Dress - prune" , "Neat and orderly" , "Tidy - clip" .)