What is unusual about the following words?

BILGE
BULB
CUSP
FILM
MORGUE
WASP
SCARCE
WOLF

Answer:

They have no rhymes (in English).

Credit: GAMES Magazine - April, 1985
Edward Dermon
RHYME SCHEME

NOTE: Other, better known, words with no English rhymes are:

ORANGE, SILVER, PURPLE, MONTH