Neckwear occasionally striped? (3)
I believe the answer is:
tie
'neckwear' is the definition.
(type of neckwear)
'occasionally striped?' is the wordplay.
'occasionally' means one should take alternating letters.
The alternating letters of 'striped' are 'TIE'.
(Other definitions for tie that I've seen before include "Bind; dead heat" , "hamper" , "restraint" , "Obligation" , "Attach, fasten" .)