Throw kitty the sponge (7)
I believe the answer is:
tosspot
'sponge' is the definition.
Both the definition and answer are singular nouns.
Maybe you can see a link between them that I can't see?
'throw kitty' is the wordplay.
'throw' becomes 'toss' (tossing is a kind of throwing).
'kitty' becomes 'pot' (both can mean a shared fund).
'toss'+'pot'='TOSSPOT'
'the' is the link.
Can you help me to learn more?
(Other definitions for tosspot that I've seen before include "supper, habitually" , "Habitual drinker" , "One drinker" , "Drunk (informal)" , "One drunkard" .)