Origin and history of stipule

Middle English stif, from Old English stif "rigid, inflexible, not easily bent," in physical senses often suggesting rigor mortis, from Proto-Germanic *stifaz "inflexible" (source also of Dutch stijf, Old Frisian stef, Old High German stif, German steif "stiff;" Old Norse stifla "choke").

The Germanic word is said to be from a PIE *stipos-, from the root *steip- "press together, pack, cram" (source also of Sanskrit styayate "coagulates," stima "slow;" Greek stia, stion "small stone," steibo "press together;" Latin stipare "pack down, compress," perhaps also stipes "post, tree trunk;" Lithuanian stipti "to stiffen, grow rigid," stiprus "strong;" Old Church Slavonic stena "wall"). However Boutkan suggests the possibility that the Germanic words are a metaphoric use from words for staff (n.).

By extension, "strong, violent; difficult to master or overcome:" In reference to battles and competitions, "fierce, stubborn, contested," mid-13c.; of winds or currents c. 1300; of liquor from 1813. In Middle English also "powerful, staunch, unmoving, resolute," and paired alliteratively with strong.

Of substances, "not fluid, thick and tenacious," early 15c. As "not natural or easy in movement," c. 1300. As "rigidly ceremonious, not easy or gracious in manner," c. 1600. To keep a stiff upper lip is attested from 1811. Related: Stiffly.

"turn (a plant) white by growing it in darkness," 1791, from French étiolé, past participle of étioler "to blanch" (17c.), perhaps literally "to become like straw," from Norman dialect étule "a stalk," Old French esteule "straw, field of stubble," from Latin stipula "straw" (see stipule). Related: Etiolated.