Fluteringly or Flutteringly: How To spell?
The word Fluteringly is misspelled against Flutteringly, an adverb meaning "In a fluttering manner."
Flutteringly has double "tt" is mispronounced as "t"Remember double 'TT' in between the strings flu & eringly which should not be misspelled with single 'T'
Wrong Spelling:  flu-t-eringly  Correct Spelling:  flu-tt-eringly 
Check more misspelled words of Flutteringly to spell it correct.