Hendecasylabic or Hendecasyllabic: How To spell?
The word Hendecasylabic is misspelled against Hendecasyllabic, an adjective meaning "Pertaining to a line of eleven syllables."
Hendecasyllabic has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings hendecasy & abic which should not be misspelled with single 'L'
Wrong Spelling:  hendecasy-l-abic  Correct Spelling:  hendecasy-ll-abic 
Find more wrongly spelled words of Hendecasyllabic to spell it well.