1. plants food Same as sweet potato (sense 1) (sense 2)
2. root vegetable: a vine root that resembles a large white floury potato and is eaten cooked as a vegetable
3. tropical plant: a tropical plant that produces yams. Genus Dioscorea.
[Late 16th century. Via Portuguese inhame or Spanish iñame< a W African language]
Regional History
In the sense "sweet potato," yam was formerly largely restricted to the South, where its use was universal. Now, through commercial usage, the term is found virtually everywhere in the United States.
