Some card games supplied by stationers (7)
I believe the answer is:
rubbers
'stationers' is the definition.
Although both the answer and definition are plural nouns, I can't understand how one could define the other.
'some card games supplied by' is the wordplay.
'some card games' becomes 'rubber' (in bridge, a rubber consists of two winning games).
'supplied' becomes 's' (this might be a standard abbreviation of which I'm unaware).
'by' means one lot of letters go next to another.
'rubber'+'s'='RUBBERS'
Can you help me to learn more?
(Other definitions for rubbers that I've seen before include "They remove lead" , "Many sets of tennis" , "sections of bridge" , "shoes?" .)