Sticky sentimentality at a party? That's okay (4-1)
I believe the answer is:
good-o
'sticky' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'sentimentality at a party? that's okay' is the wordplay.
I cannot really understand how this works, but
'sentimentality' could be 'goo' (informal term for sentimentality) and 'goo' is found within the answer.
'party?' could be 'do' (do is a kind of party) and 'do' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for good-o that I've seen is " Expression of pleasure".)