Wash some gear in secret (5)
I believe the answer is:
rinse
'wash' is the definition.
(rinse is a kind of wash)
'some gear in secret' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'RINSE' is hidden in the letters of 'gear in secret'.
(Other definitions for rinse that I've seen before include "Wash - siren (anag)" , "Hair preparation" , "Hair tint" , "Wash without using soap" , "Wash lightly without soap" .)