Outsiders from Romania wearing varieties of animal pelt (4,4,3,4)
I believe the answer is:
rain cats and dogs
'pelt' is the definition.
(synonyms)
'outsiders from romania wearing varieties of animal' is the wordplay.
'outsiders from' suggests removing the centre (letters on the outside of the word).
'wearing' becomes 'in' (as in being 'in' certain clothes).
'varieties of animal' becomes 'cats and dogs' (cats and dogs are animals).
'romania' with its middle removed is 'ra'.
'ra'+'in'+'catsanddogs'='RAIN CATS AND DOGS'
(Other definitions for rain cats and dogs that I've seen before include "come down hard" , "Pour" , "To fall heavily" , "bucket" , "Pelt" .)