look vs titter

look

noun
  • A facial expression. 

  • Physical appearance, visual impression. 

  • The action of looking; an attempt to see. 

intj
  • Pay attention. 

verb
  • As a transitive verb, often in the imperative; chiefly takes relative clause as direct object. 

  • To make sure of, to see to. 

  • To look at a pitch as a batter without swinging at it. 

  • To give an appearance of being. 

  • To express or manifest by a look. 

  • To face or present a view. 

  • To expect or anticipate. 

  • As an intransitive verb, often with "at". 

  • To search for, to try to find. 

  • To appear, to seem. 

titter

noun
  • A nervous or somewhat repressed giggle. 

  • A woman's breast. 

verb
  • To laugh or giggle in a somewhat subdued or restrained way, as from nervousness or poorly-suppressed amusement. 

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