Sinistraly or Sinistrally: How To spell?
The word Sinistraly is misspelled against Sinistrally, an adverb meaning "Toward the left; in a sinistral manner."
Sinistrally has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings sinistra & y which should not be misspelled with single 'L'
Wrong Spelling:  sinistra-l-y  Correct Spelling:  sinistra-ll-y 
Find more wrongly spelled words of Sinistrally to spell it well.