betrothen vs better half

betrothen

noun

  • One who is betrothen or betrothed, i.e. a fiancé or fiancée. 

adj

  • Betrothed 

better half

noun

  • A person's spouse or lover, most commonly a man's wife. 

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