Rum parties for weirdos (8)
I believe the answer is:
oddballs
'weirdos' is the definition.
(I've seen this before)
'rum parties' is the wordplay.
'rum' becomes 'odd' (I've seen this before).
'parties' becomes 'balls' (ball is a kind of party).
'odd'+'balls'='ODDBALLS'
'for' is the link.
(Other definitions for oddballs that I've seen before include "Strange or eccentric people" , "peculiar characters" , "Weirdos" , "Bold lads? (anag)" , "Eccentric types" .)