Perfumed powder found in metal crate (4)
I believe the answer is:
talc
'perfumed powder' is the definition.
(I've seen this in another clue)
'in metal crate' is the wordplay.
'in' says the answer is hidden in the clue.
'TALC' can be found hidden inside 'metal crate'.
'found' is the link.
(Other definitions for talc that I've seen before include "Softest substance in Mohs scale of hardness" , "It is used to absorb moisture" , "Mineral used as a toiletry" , "Softest mineral on Mohs hardness scale" , "White powder for the bathroom" .)