unneededly vs vainly

unneededly

adv
  • In an unneeded manner; not neededly. 

vainly

adv
  • With a vain attitude; in a self-approving manner. 

  • In a vain pursuit; to no avail. 

How often have the words unneededly and vainly occurred in a corpus of books? (source: Google Ngram Viewer )