Strange Manx cat causing disturbance (6)
I believe the answer is:
rumpus
'disturbance' is the definition.
(rumpus is a kind of disturbance)
'strange manx cat' is the wordplay.
'strange' becomes 'rum' (I've seen this before).
'manx' means to remove the last letter (Manx cats have no tail).
'cat' becomes 'puss' (puss is a kind of cat).
'puss' with its last letter taken away is 'pus'.
'rum'+'pus'='RUMPUS'
'causing' is the link.
(Other definitions for rumpus that I've seen before include "Tumult" , "To-do" , "Hullabaloo" , "Kerfuffle" , "Noisy brawl" .)