especially vs oftest

especially

adv
  • In a special manner; specially. 

  • Used to place greater emphasis upon someone or something. 

  • Particularly; to a greater extent than is normal. 

oftest

adv
  • Most often (superlative form of oft: most oft) 

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