ambivalent vs co-ed

ambivalent

adj
  • Alternately having one opinion or feeling, and then the opposite. 

  • Simultaneously experiencing or expressing opposing or contradictory feelings, beliefs, or motivations. 

co-ed

adj
  • Of an educational institution, that teaches both males and females. 

  • Of any location, that mixes males and females. 

How often have the words ambivalent and co-ed occurred in a corpus of books? (source: Google Ngram Viewer )