Lawyers - underwear (6)
I believe the answer is:
briefs
'lawyer's underwear' is the definition.
'briefs' can be an answer for 'underwear' (I've seen this before). I am not certain of the 'lawyer's' bit.
'lawyer's underwear' is the wordplay.
'lawyer' becomes 'brief' (I've seen this before).
'underwear' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'brief'+'s'='BRIEFS'
Can you help me to learn more?
(Other definitions for briefs that I've seen before include "Documents stating facts and points of law" , "Supplies dope" , "Barristers' cases or advices" , "Garments" , "Underpants for lawyers?" .)