alfalfa (n.)

1845, from Spanish alfalfa, earlier alfalfez, said by Iberian sources to be from Arabic al-fisfisa "fresh fodder." Watkins says ultimately from Old Iranian compound *aspa-sti- "alfalfa, clover," from *aspa- "horse" (from PIE root *ekwo- "horse") + -sti- "food," from suffixed form of PIE root *ed- "to eat."