escalator (n.)

1590s, "action of using ladders to scale the walls of a fortified place," from French escalade (16c.) "an assault with ladders on a fortification," from Italian scalata, fem. past participle of scalare "to climb by means of a ladder," from scala "ladder," related to Latin scandere "to climb" (see scan). For initial e-, see e-. Also in early use in English in Spanish form escalada, later corrupted to escalado. As the name of a brand of luxury SUV by Cadillac, from 1999.

1640s, originally of muscles which raise a part of the body, from Latin elevator "one who raises up," agent noun from past participle stem of elevare (see elevate). As a name for a mechanical lift (originally for grain) attested from 1787. Elevator music for bland, low-volume background music meant to relax listeners is attested by 1963. Elevator as a lift for shoes is from 1940.

1922, "to use an escalator," back-formation from escalator, replacing earlier verb escalade (1801), from the noun escalade. Escalate came into general use with a figurative sense of "raise" from 1959 (intrans.), originally in reference to scenarios for possible nuclear war. Related: Escalated; escalating. Transitive figurative sense is by 1962.