Neckwear cloth, loose, I’d rearranged (3,6,3)
I believe the answer is:
old school tie
'neckwear' is the definition.
(old school tie is a kind of neckwear)
'cloth loose i'd rearranged' is the wordplay.
'rearranged' indicates anagramming the letters.
'cloth'+'loose'+'id'='clothlooseid'
'clothlooseid' with letters rearranged gives 'OLD SCHOOL TIE'.
(Other definitions for old school tie that I've seen before include "Symbol of private education" , "Loyalty of those educated together" , "Symbol of upper class solidarity" , "A source of unfair advantage" , "Term for group loyalty of those with posh private eduction" .)