porpoise vs tit

porpoise

noun
  • Any small dolphin. 

  • A small cetacean of the family Phocoenidae, related to dolphins and whales. 

verb
  • Said of an air-breathing aquatic animal such as a porpoise or penguin: To repeatedly jump out of the water to take a breath and dive back in a continuous motion. 

  • Said of an aircraft: to make a series of plunges when taking off or landing; or of a watercraft: to successively plunge up and down in the water. 

tit

noun
  • Any of various other small passerine birds. 

  • A person's breast or nipple. 

  • A chickadee; a small passerine bird of the genus Parus or the family Paridae, common in the Northern Hemisphere. 

  • An idiot; a fool. 

  • A morsel; a bit. 

  • A police officer; a "tithead". 

  • A mammary gland, teat. 

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