Terrasylable or Terrasyllable: How To spell?

The word Terrasylable is misspelled against Terrasyllable, a noun meaning "A word consisting of four syllables; a quadrisyllable."

Terrasyllable has double "ll" is mispronounced as "l"
Remember double 'LL' in between the strings terrasy & able which should not be misspelled with single 'L'
Wrong Spelling:  terrasy-l-able 
Correct Spelling:  terrasy-ll-able 
Explore spell check of Terrasyllable to spell without errors.