Fancy toy did something unusual (6)
I believe the answer is:
oddity
'something unusual' is the definition.
(I've seen this before)
'fancy toy did' is the wordplay.
'fancy' indicates anagramming the letters.
'toy'+'did'='toydid'
'toydid' is an anagram of 'ODDITY'.
(Other definitions for oddity that I've seen before include "rare thing" , "Something peculiar, person or event" , "Family relative" , "Something strange or eccentric" , "David Bowie's Space ___" .)