Weird thing, darkness (5)
I believe the answer is:
night
'darkness' is the definition.
(night is a kind of darkness)
'weird thing' is the wordplay.
'weird' indicates anagramming the letters.
'thing' anagrammed gives 'NIGHT'.
(Other definitions for night that I've seen before include "Time of darkness" , "Time without 10" , "See 9" , "8d [DARKNESS]" , "Sunset to sunrise" .)