Ballonist or Balloonist: How To spell?
The word Ballonist is misspelled against Balloonist, a noun meaning "An aeronaut."
Balloonist has double "oo" is mispronounced as "o"Remember double 'OO' in between the strings ball & nist which should not be misspelled with single 'O'
Wrong Spelling:  ball-o-nist  Correct Spelling:  ball-oo-nist 
Find more incorrect spellings of Balloonist to spell right way.