lovebird vs lover

lovebird

noun
  • One of the members of an openly affectionate couple. 

  • Any small parrot from one of the nine species within the genus Agapornis. Sometimes they are kept as cage birds and are noted for their affection towards each other. 

verb
  • To express romantic affection openly. 

lover

noun
  • A sexual partner, especially one with whom someone is having an affair. 

  • A person who loves something. 

  • An informal term of address for any friend. 

  • One who loves and cares for another person in a romantic way; a sweetheart, love, soulmate, boyfriend, girlfriend, or spouse. 

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