"small firearm with a curved handle, intended to be held in one hand when aimed and fired," 1570s, from French pistole "short firearm" (1566), a word of uncertain origin, sometimes said to be from German Pistole, from Czech pis'tala "firearm," literally "tube, pipe," from pisteti "to whistle," a word of imitative origin, related to Russian pischal "shepherd's pipe."

But the earlier English form pistolet (1550) is said to be from French pistolet "a small firearm," also "a small dagger," which is said to be connected with Italian pistolese, in reference to Pistoia, the town in Tuscany noted for gunsmithing.

Pistol-whip (v.) "strike (someone) with the butt of a pistol is recorded by 1942. Pistol-grip "handle shaped like the butt of a pistol" is by 1874.

"the primitive backbone," 1848, coined in English by English anatomist Sir Richard Owen from chord (n.2) + Greek nōton "back," which is perhaps from the same PIE source as Latin natis "buttock," which is the source of Italian and Spanish nalga, Old French nache "buttock, butt." Related: Notochordal.

1530s, "to poke with a stick," of uncertain origin; possibly [Barnhart, Century Dictionary] a variant of brod, from Middle English brodden "to goad," from Old Norse broddr "shaft, spike" (see brad), or perhaps imitative [OED]. Compare dialectal prog "pointed instrument for poking" (1610s), also as a verb, "to poke about." 

Figurative sense of "mental incitement or instigation" is by 1871. Related: Prodded; prodding.

zodiacal constellation usually identified as "the Ram," late Old English, from Latin aries "ram" (related to arietare "to butt"), from a PIE root meaning "spring, jump" (source also of Lithuanian ėrytis, Old Church Slavonic jarici, Armenian oroj "lamb;" Greek eriphos, Old Irish heirp "kid"). Meaning "person born under the sign of Aries" is from 1894; they also have been called Arian (1917).

c. 1400, "of or like a ray or radius," from Medieval Latin radialis, from Latin radius "shaft, rod; spoke of a wheel; beam of light" (see radius). Meaning "arranged like the radii of a circle" is by 1750. As a noun, "a radiating or radial part," by 1872. As a type of tire, attested from 1965, short for radial-ply (tire), so called because the cords run at right angles to the circumference. Related: Radially.

"weapon with a penetrating head and a long wooden shaft, meant to be thrust or thrown," Old English spere "spear, javelin, lance," from Proto-Germanic *sperō (source also of Old Norse spjör, Old Saxon, Old Frisian sper, Dutch speer, Old High German sper, German Speer "spear"), from PIE root *sper- (1) "spear, pole" (source also of Old Norse sparri "spar, rafter," and perhaps also Latin sparus "hunting spear").