There's a small collection of (multisyllabic) English words and names that end in -oon. Although it's hard to assign them a common linguistic origin or etymology, they nonetheless seem to constitute an uncommonly colorful and garish subset of the language. If you were going to have a party, this is the set of words to invite!
I am sorely tempted to Croon a Tune to Oona or Mourn a Rune to Lorna Doone using only these words as rhymes.
You can go to the wordplay home page.