ac vs although

ac

noun
  • account; money of account 

  • alicyclic 

adj
  • ante cibum, before meals 

although

conj
  • Though, even though, in spite of or despite the fact that: introducing a clause that expresses a concession. 

  • But, except. 

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