eighth month, late 11c., from Latin Augustus (mensis), sixth month of the later Roman calendar, renamed from Sextilis (literally "sixth") in 8 B.C.E. to honor emperor Augustus Caesar, literally "Venerable Caesar" (see august (adj.), and compare Augustus). One of two months given new names to honor Roman leaders (July being the other), the Romans also gave new imperial names to September (Germanicus) and October (Domitian) but these did not stick.
In England, the name replaced native Weodmonað "weed month." Traditionally the first month of autumn in Great Britain, the last of summer in the U.S.
1540s in botany, a large genus of plants that include the milkvetch, loco-weed and goat's thorn; 1560s in anatomy in reference to a type of bone, usually in or near the ankle. Historically these bones, especially those taken from deer, were used as a type of die for games and fortune telling. It is attested from 1560s in architecture as a type of molding. All senses are from Greek astragalos "neck vertebra; ankle bone; knuckle-bones (used as dice)," which generally is considered to be from the same root as osteon "a bone" (see osteo-), but Beekes says they are unrelated.
"seaweed," 1590s, from Portuguese sargasso "seaweed," which is perhaps from sarga, a type of grape (on this theory, the sea plant was so called from its berry-like air sacs; it also is known as grapeweed), or from Latin sargus, a kind of fish found in the Mediterranean and eastern Atlantic, from Greek sargos, name of a sea-fish that appears in schools, a word of uncertain origin.
The name Sargasso Sea is attested by 1819 for the large section of the Atlantic in the interior of the great loop of the Gulf Stream, where this sort of weed abounds and could impede sailing ships. Hence figurative for any sort of stagnant mass.
"movable or removable cover for a pot, etc.," mid-13c., from Old English hlid "covering, opening, gate," from Proto-Germanic *hlidan "a cover," literally "that which bends over" (source also of Old Norse hlið "gate, gap," Swedish lid "gate," Old French hlid, Middle Dutch lit, Dutch lid, Old High German hlit "lid, cover"), from PIE *klito-, from root *klei- "to lean."
Meaning "eyelid" is from early 13c. Slang sense of "hat, cap" is attested from 1896. As a measure of marijuana, one ounce, 1967, presumably the amount of dried weed that would fit in some commercial jar lid. Slang phrase put a lid on "clamp down on, silence, end" is from 1906; many figurative senses are from the image of a pot boiling over.
"large nail," mid-14c., perhaps from or related to a Scandinavian word, such as Old Norse spik "splinter," Middle Swedish spijk "nail," from Proto-Germanic *spikaz (source also of Middle Dutch spicher, Dutch spijker "nail," Old English spicing "large nail," Old English spaca, Old High German speihha "spoke"), from PIE root *spei- "sharp point" (source also of Latin spica "ear of corn," spina "thorn, prickle, backbone," and perhaps pinna "pin" (see pin (n.)); Greek spilas "rock, cliff;" Lettish spile "wooden fork;" Lithuanian speigliai "thorns," spitna "tongue of a buckle," Old English spitu "spit").
The English word also might be influenced by and partly a borrowing of Latin spica (see spike (n.2)), from the same root. Slang meaning "needle" is from 1923. Meaning "pointed stud in athletic shoes" is from 1832. Electrical sense of "pulse of short duration" is from 1935.
tall weed of the figwort family, used medicinally, early 14c., molein, probably from Anglo-French moleine (Modern French molène), perhaps literally "the soft-leaved plant," from French mol "soft," from Latin mollis "soft" (from PIE root *mel- (1) "soft"). This connection was felt in Middle English, and the word soft was used as an alternate name for the plant (early 14c.)
There is an Old English word molegn or moleȝn, which Cockayne identifies as mullein. The word is glossed in a manuscript with Latin calmum and Old English windelstreow, both of which suggest something straw-like, though this does not necessarily exclude mullein with its tall stalk and little stubble-like hairs. If the identification is correct, this would upset the French etymology.