Maid dons new suit (8)
I believe the answer is:
diamonds
'suit' is the definition.
(I know this)
'maid dons new' is the wordplay.
'new' indicates anagramming the letters.
'maid'+'dons'='maiddons'
'maiddons' is an anagram of 'DIAMONDS'.
(Other definitions for diamonds that I've seen before include "Precious stones; suit" , "Precious stones found amid nods" , "Gemstones and card suit" , "Suit - sparklers" , "rocks?" .)