as vs even though

as

conj
  • Being that, considering that, because, since. 

  • used before a preposition to clarify that the prepositional phrase restricts the meaning of the sentence; specifically. 

  • At the same instant or moment that: when. 

  • Varying through time in the same proportion that. 

  • In the (same) way or manner that; to the (same) degree that. 

  • Functioning as a relative conjunction, and sometimes like a relative pronoun: that, which, who. (See usage notes.) 

  • At the same time that, during the same time when: while. 

  • Expressing concession: though. 

  • Used after so or as to introduce a comparison. 

  • Used to introduce a result: with the result that it is. 

adv
  • Considered to be, in relation to something else; in the relation (specified). 

  • To such an extent or degree; to the same extent or degree. 

  • Used to intensify an adjective; very much; extremely 

prep
  • Introducing a basis of comparison, with an object in the objective case. 

  • In the role of. 

  • by way of 

noun
  • Any of several coins of Rome, coined in bronze or later copper; or the equivalent value. 

  • A libra. 

even though

conj
  • Although; though; despite or in spite of the fact that. 

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