A lip split by a bucket (4)
I believe the answer is:
pail
'a bucket' is the definition.
(synonyms)
'a lip split' is the wordplay.
'split' indicates anagramming the letters (letters split up and reassembled).
'a'+'lip'='alip'
'alip' is an anagram of 'PAIL'.
'by' acts as a link.
(Other definitions for pail that I've seen before include "Open-topped container" , "Container; sounds like dim" , "A bucket - the kind Jack and Jill used" , "Cylindrical vessel" , "it may go down well" .)