Wearing underwear, hiding bottom quickly (2,5)
I believe the answer is:
in brief
'quickly' is the definition.
(I've seen this in another clue)
'wearing underwear hiding bottom' is the wordplay.
I cannot quite see how this works, but
'wearing' could be 'in' (as in being 'in' certain clothes) and 'in' is located in the answer.
The remaining letters 'brief' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for in brief that I've seen before include "To sum up" , "shortly" , "Taking just a few words" , "Where barrister finds the facts" , "Where the solicitor should look for advice" .)