Short dictionary (pocket) that used to be kept by the bed (10)
I believe the answer is:
chamberpot
'that used to be kept by the bed' is the definition.
(chamberpots were historically kept by beds)
'short dictionary pocket' is the wordplay.
'short' means to remove the last letter.
'dictionary' becomes 'chambers' (dictionary publisher).
'pocket' becomes 'pot' (as in to pot or pocket a ball in snooker).
'chambers' with its last letter taken away is 'chamber'.
'chamber'+'pot'='CHAMBERPOT'
(Other definitions for chamberpot that I've seen before include "that was kept under the bed" , "wee vessel" .)