a tad vs somewhatly

a tad

adv

  • Slightly; rather. 

  • Very. 

  • A lot. 

  • To a small extent; in a small amount. 

somewhatly

adv

  • somewhat; to some degree 

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