Drunkard -- she regularly conceals bad smell (6)
I believe the answer is:
sponge
'drunkard' is the definition.
(I've seen this in another clue)
'she regularly conceals bad smell' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'conceals' indicates putting letters inside.
'bad smell' becomes 'pong' (pong can informally mean a bad smell).
The alternating letters of 'she' are 'se'.
'se' placed around 'pong' is 'SPONGE'.
(Other definitions for sponge that I've seen before include "Sea animal often found in bathroom" , "Absorbing" , "'Porous, absorbent substance (6)'" , "Marine creature - cadge" , "Porous substance found in the ocean" .)