Infinitesimaly or Infinitesimally: How To spell?
The word Infinitesimaly is misspelled against Infinitesimally, an adverb meaning "By infinitesimals; in infinitely small quantities; in an infinitesimal degree."
Infinitesimally has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings infinitesima & y which should not be misspelled with single 'L'
Wrong Spelling:  infinitesima-l-y  Correct Spelling:  infinitesima-ll-y 
Find more wrongly spelled words of Infinitesimally to spell it well.