Decenaries or Decennaries: How To spell?
The word Decenaries is misspelled against Decennaries, which is plural of "Decennary"
Decennaries has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings dece & aries which should not be misspelled with single 'N'
Wrong Spelling:  dece-n-aries  Correct Spelling:  dece-nn-aries 
Find more wrongly spelled words of Decennaries to spell it well.