Soak Arab in spouse's clothing (8)
I believe the answer is:
marinate
'soak' is the definition.
(I've seen this before)
'arab in spouse's clothing' is the wordplay.
'arab' becomes 'ar' (abbreviation in Chambers).
'spouse' becomes 'mate' (synonyms).
'clothing' is an insertion indicator (some letters cover up or clothe others).
'ar'+'in'='arin'
'arin' put within 'mate' is 'MARINATE'.
(Other definitions for marinate that I've seen before include "Rain team (anag.)" , "Soak or steep meat or fish" , "Soak food in flavoured liquid before cooking" , "Steep before cooking" , "Soak food in a minaret" .)