As nouns the difference between flunker and lunker
is that flunker is someone who has failed in an examination while lunker is (us) anything, especially a game fish, that is especially large for its type; a whopper.
flunker
English
Noun
(
en noun)
Someone who has failed in an examination lunker
English
Noun
(
en noun)
(US) Anything, especially a game fish, that is especially large for its type; a whopper.