Droner or Drainer: How To spell?

The word Droner is misspelled against Drainer, a noun meaning "One who, or that which, drains."

Word contains consecutive vowels 'AI' in between alphabets dr & ner is misspelled as 'O'
Wrong Spelling:  dr-o-ner 
Correct Spelling:  dr-ai-ner 
Find more incorrect spellings of Drainer to spell right way.

You might be interested to know

Evaporove or Evaporaive?

Floly or Flaily?

Glor or Glair?