ambulanceyoudaoicibaDictYouDict[ambulance 词源字典]
ambulance: [19] Originally, ambulance was a French term for a field hospital – that is, one set up at a site convenient for a battlefield, and capable of being moved on to the next battlefield when the army advanced (or retreated). In other words, it was an itinerant hospital, and the ultimate source of the term is the Latin verb ambulāre ‘walk’ (as in amble). The earliest recorded term for such a military hospital in French was the 17th-century hôpital ambulatoire.

This was later replaced by hôpital ambulant, literally ‘walking hospital’, and finally, at the end of the 18th century, by ambulance. This sense of the word had died out by the late 19th century, but already its attributive use, in phrases such as ambulance cart and ambulance wagon, had led to its being used for a vehicle for carrying the wounded or sick.
=> acid, alacrity, amble, perambulator[ambulance etymology, ambulance origin, 英语词源]
ambulance (n.)youdaoicibaDictYouDict
1798, "mobile or field hospital," from French (hôpital) ambulant, literally "walking (hospital)," from Latin ambulantem (nominative ambulans), present participle of ambulare "to walk" (see amble).
AMBULANCE, s. f. a moveable hospital. These were houses constructed in a manner so as to be taken to pieces, and carried from place to place, according to the movements of the army; and served as receptacles in which the sick and wounded men might be received and attended. ["Lexicographica-Neologica Gallica" (The Neological French Dictionary), William Dupré, London, 1801]
The word was not common in English until the meaning transferred from "field hospital" to "vehicle for conveying wounded from field" (1854) during the Crimean War. In late 19c. U.S. the word was used dialectally to mean "prairie wagon." Ambulance-chaser as a contemptuous term for a type of lawyer dates from 1897.