Where does the word potato come from?

The word potato is from Spanish patata, from the word batata in the Taino native dialect of the Americas, which meant "sweet potato."

The standard potato, Solanum tuberosum, was originally cultivated in Chile and Peru, and discovered there by the Spanish conquistafors in the early 1500's. From there, it was transplanted to Europe and to North America.
First attest in 1565, from Spanish patata, from Carib (Haiti) batata "sweet potato."
1565, from the Spanish patata (white potato), from Taino batata (sweet potato).
In the mid 16th century it came from the Spanish patata, its a variant of Taino batata 'sweet potato'. The English word originally denoted the sweet potato and gained its current sense in the late 16th century.