1809, "mobile or field hospital," from Fr. (hôpital) ambulant,
lit. "walking (hospital)," from L. ambulans
), from ambulare
"to walk" (see amble
). Not common until meaning transferred from "field hospital" to "vehicle for conveying wounded from field" (1854) during the Crimean War. Ambulance-chaser
as a contemptuous term for a type of lawyer dates from 1897.