New Escort model is a tight fit! (6)
I believe the answer is:
corset
'model is a tight fit' is the definition.
I can't judge whether this definition defines the answer.
'new escort' is the wordplay.
'new' indicates an anagram.
'escort' with letters rearranged gives 'CORSET'.
Can you help me to learn more?
(Other definitions for corset that I've seen before include "Tight-fitting ladies' garment" , "Stays" , "Restraining undergarment" , "Item of underwear" , "fat controller?" .)