Overwhelm with work on printing-machine (7)
I believe the answer is:
oppress
'overwhelm' is the definition.
(thesaurus)
'work on printing-machine' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'on' says to put letters next to each other.
'printing machine' becomes 'press' (I've seen this before).
'op'+'press'='OPPRESS'
'with' is the link.
(Other definitions for oppress that I've seen before include "Burden" , "Govern cruelly" , "Keep in subjection and hardship" , "Keep someone down" , "Bear down hard on" .)