Large pair of spectacles used for card-game (3)
I believe the answer is:
loo
'for card-game' is the definition.
(I've seen this before)
'large pair of spectacles' is the wordplay.
'large' becomes 'l'.
'pair of spectacles' becomes 'oo' (OO looks like spectacles).
'l'+'oo'='LOO'
'used' acts as a link.
(Other definitions for loo that I've seen before include "Privy" , "In which one goes" , "WC - old card game" , "Card game; the 'smallest room'" , "Ladies, perhaps" .)