This could describe slug under the table (7)
I believe the answer is:
legless
This clue is a double definition.
'this could describe slug' is the first definition.
(I know that slugs are legless)
'under the table' is the second definition.
(I've seen this before)
(Other definitions for legless that I've seen before include "Such a person cannot stand" , "Drunk (as a worm?)" , "as a snake" , "like a fish?" , "Sozzled - lacking limbs" .)