Wild parties a host has to put up with (8)
I believe the answer is:
parasite
'host has to put up with' is the definition.
(I've seen this before)
'wild parties a' is the wordplay.
'wild' indicates anagramming the letters.
'parties'+'a'='partiesa'
'partiesa' is an anagram of 'PARASITE'.
(Other definitions for parasite that I've seen before include "Organism that lives on another" , "host has to put up with" , "mistletoe sprig can be" , "Say mistletoe" , "sponge" .)