The discontented dons curse warm clothing (7)
I believe the answer is:
sweater
'warm clothing' is the definition.
'the discontented dons curse' is the wordplay.
'discontented' suggests removing the centre.
'dons' indicates putting letters inside (don means to wear or put on).
'curse' becomes 'swear' (synonyms).
'the' with its middle removed is 'te'.
'te' going inside 'swear' is 'SWEATER'.
(Other definitions for sweater that I've seen before include "person in a sauna?" , "Clobber" , "Top" , "Jumper or jersey" , "Re waste: it's a garment" .)