potato vs yam

potato

noun
  • The tuber of a plant, Solanum tuberosum, eaten as a starchy vegetable, particularly in the Americas and Europe; this plant. 

  • Metaphor for a person or thing of little value. 

  • A camera that takes poor-quality pictures. 

  • A mentally handicapped person. 

  • A conspicuous hole in a sock or stocking. 

  • An underpowered computer or other device, especially when small in size. 

adj
  • Underpowered; low-end. 

yam

noun
  • The edible, starchy, tuberous root of that plant, a tropical staple food. 

  • An orange-brown colour, like the flesh of the yam. 

  • A potato. 

  • home 

  • Any climbing vine of the genus Dioscorea in the Eastern and Western hemispheres, usually cultivated. 

  • A sweet potato; a tuber from the species Ipomoea batatas. 

  • A oca; a tuber from the species Oxalis tuberosa. 

  • Taro. 

verb
  • To eat. 

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