Verge to trim, about to be overlooked (3)
I believe the answer is:
lip
'verge' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for lip that I've seen before include "sauciness" , "Rim; impudence (slang)" , "Aural impudence" , "Insolence (slang)" , "giving such insincere service" .)