Maybe grease two zips (3)
I believe the answer is:
goo
'maybe grease' is the definition.
The answer and definition can be both substances as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'two zips' is the wordplay.
'two zips' can mean two substitutions for 'zip'.
'zip' becomes 'go' (both can mean energy or enthusiasm).
'zip' becomes 'o' (zip can mean zero).
'go'+'o'='GOO'
Can you help me to learn more?
(Other definitions for goo that I've seen before include "Sticky gunge" , "Viscous matter" , "Sticky substance (colloq.)" , "Substance that's viscous" , "Slime" .)