Bad dictionary does contain word for slave (6)
I believe the answer is:
addict
'word for slave' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'bad dictionary does contain' is the wordplay.
'contain' indicates the answer is hidden within the clue (words from the clue contain the answer).
'ADDICT' is hidden within 'bad dictionary does'.
Can you help me to learn more?
(Other definitions for addict that I've seen before include "Person compulsively given to taking drugs" , "One hooked on something" , "Drug dependant" , "Junkie, substance abuser" , "One dependent on drugs" .)