Youthful setter perhaps squeezing trendy model (3-2)
I believe the answer is:
pin-up
'model' is the definition.
(pin-up is a kind of model)
'youthful setter perhaps squeezing trendy' is the wordplay.
'youthful setter perhaps' becomes 'pup' (setter is a type of dog).
'squeezing' indicates putting letters inside (squeeze can mean hug or embrace).
'trendy' becomes 'in'.
'pup' placed around 'in' is 'PIN-UP'.
(Other definitions for pin-up that I've seen before include "picture of heart-throb?" , "Alluring poster" , "Attractive celebrity" , "Object of (sexual) admiration" , "Attach (to a notice board)" .)