addedly vs either

addedly

adv
  • In addition; additionally. 

either

adv
  • As well. 

det
  • Any one (of two). 

  • Each of two; both. 

pron
  • One or the other of two people or things. 

conj
  • Introduces the first of two (or occasionally more) options or possibilities, the second (or last) of which is introduced by “or”. 

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