Small hamper for kind of party (7)
I believe the answer is:
slumber
'kind of party' is the definition.
'small hamper' is the wordplay.
I cannot quite see how this works, but
'small' could be 's' (abbreviation - e.g. clothes size) and 's' is located in the answer.
The remaining letters 'lumber' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'for' acts as a link.
Can you help me to learn more?
(Other definitions for slumber that I've seen before include "Snooze" , "Rumbles (anag.)" , "Doze" , "nap" , "Overnight social event for (American) teenage girls" .)