late 14c., "movable joint of a gate or door," not found in Old English, cognate with Middle Dutch henghe "hook, handle," Middle Low German henge "hinge," from Proto-Germanic *hanhan (transitive), *hangen (intransitive), from PIE *konk- "to hang" (see hang (v.)). The notion is the thing from which a door hangs. Figurative sense of "that on which events, etc., turn" is from c.1600. Stamp-collecting sense is from 1883.
"making revolutions, rotating," 1690s, present-participle adjective from revolve (v.). Revolving door is attested from 1856 in industrial processes, 1896 in buildings.
1520s, "act of entering," from French entrance, from entrer (see enter). Sense of "door, gate" first recorded in English 1530s. Meaning "a coming of an actor upon the stage" is from c. 1600.
framed part of a window, into which the panes are fitted, 1680s, sashes, a mangled Englishing of French châssis "frame" of a window or door (see chassis).
The word was mistaken as a plural and further mangled by loss of the -s by 1704. Sash-door, one having panes of glass to admit light, is by 1726; sash-weight, attached by cords to either side of a sash to balance it and make it easier to raise and lower, is attested by 1737.
"involving or characterized by prudence," mid-15c., prudencial, from Medieval Latin prudentialis, from Latin prudentia "a foreseeing, foresight" (see prudence). Related: Prudentially.
Prudential, the U.S. insurance company, dates to the 1870s; its logo featuring the Rock of Gibraltar dates from c. 1900 and was widely known 20c. The Prudential of Great Britain is a different company, founded 1848 to provide loans to professional and working people, noted for its door-to-door agents ("the Man from the Pru").