Etymology
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nose (v.)

1570s, "perceive the smell of;" 1640s; "pry, search in a meddlesome way;" from nose (n.). Related: Nosed; nosing.

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by (prep., adv.)

Old English be- (unstressed) or bi (stressed) "near, in, by, during, about," from Proto-Germanic *bi "around, about," in compounds often merely intensive (source also of Old Saxon and Old Frisian bi "by, near," Middle Dutch bie, Dutch bij, German bei "by, at, near," Gothic bi "about"), from PIE *bhi, reduced form of root *ambhi- "around."

As an adverb by c. 1300, "near, close at hand." OED (2nd ed. print) has 38 distinct definitions of it as a preposition. Originally an adverbial particle of place, which sense survives in place names (Whitby, Grimsby, etc., also compare rudesby). Elliptical use for "secondary course" was in Old English (opposed to main, as in byway, also compare by-blow "illegitimate child," 1590s, Middle English loteby "a concubine," from obsolete lote "to lurk, lie hidden"). This also is the sense of the second by in the phrase by the by (1610s). By the way literally means "along the way" (c. 1200), hence "in passing by," used figuratively to introduce a tangential observation ("incidentally") by 1540s.

To swear by something or someone is in Old English, perhaps originally "in the presence of." Phrase by and by (early 14c.) originally meant "one by one," with by apparently denoting succession; modern sense of "before long" is from 1520s. By and large "in all its length and breadth" (1660s) originally was nautical, "sailing to the wind and off it," hence "in one direction then another;" from nautical expression large wind, one that crosses the ship's line in a favorable direction.

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lead (n.1)

heavy metal, Old English lead "lead, leaden vessel," from West Germanic *lauda- (source also of Old Frisian lad, Middle Dutch loot, Dutch lood "lead," German Lot "weight, plummet"), a word of uncertain origin. The name and the skill in using the metal seem to have been borrowed from the Celts (compare Old Irish luaide).

Figurative of heaviness at least since early 14c. American English slang lead balloon "dismal failure" attested by 1957, perhaps 1940s (as a type of something heavy that can be kept up only with effort, from 1904). Lead-footed "slow" is from 1896; opposite sense of "fast" emerged 1940s in trucker's jargon, from notion of a foot heavy on the gas pedal.

Meaning "graphite in a pencil" is from 1816 (see pencil (n.)). Black lead was an old name for "graphite," hence lead pencil (1680s) and the colloquial figurative phrase to have lead in one's pencil "be possessed of (especially male sexual) vigor," attested by 1902. White lead (1560s) was an old name for "tin."

As a name of a dull bluish-gray color, 1610s. From 1590s as figurative for "bullets." Lead oxide was much used in glazing, mirror-making, and pigments. In printing, "thin strip of type-metal (often lead but sometimes brass) used in composition to separate lines" from 1808, earlier space-line. Lead-poisoning is from 1848; earlier lead-distemper (1774).

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lead (n.2)
c. 1300, "action of leading," from lead (v.1). Meaning "the front or leading place" is from 1560s. Johnson stigmatized it as "a low, despicable word." Sense in card-playing, "action or privilege of playing first," is from 1742; in theater, "the principal part," from 1831; in journalism, "initial summary of a news story," from 1912 (often spelled lede to distinguish it from lead (n.1), which formerly played a prominent role in typesetting. Boxing sense is from 1906. In jazz bands, from 1934 in reference to the principal parts; earlier it was used in music in reference to fugues (1880) of the part that takes off first and is "followed" by the others.

Meaning "direction given by example" (as in follow (someone's) lead) is by 1863, that of "a clue to a solution" is by 1851, both from the notion of "thing to be followed." As an adjective, "leading," by 1846. Lead-time "time needed to produce something" is 1945, American English.
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lead (v.2)
early 15c., "to make of lead," from lead (n.1). Meaning "to cover with lead" is from mid-15c. In printing, 1841, also lead out.
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lead (adj.)
"made of or resembling lead," late 14c., from lead (n.1).
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lead (v.1)

"to guide," Old English lædan (transitive) "cause to go with oneself; march at the head of, go before as a guide, accompany and show the way; carry on; sprout forth, bring forth; pass (one's life)," causative of liðan "to travel," from Proto-Germanic *laidjanan (source also of Old Saxon lithan, Old Norse liða "to go," Old High German ga-lidan "to travel," Gothic ga-leiþan "to go"), from PIE *leit- (2) "to go forth."

Of roads, c. 1200. Meaning "to be in first place" is from late 14c. Intransitive sense, "act the part of a leader," is from 1570s. Sense in card playing, "to commence a round or trick," is from 1670s. Meaning "take the directing part in a musical performance or prayer" is from 1849. Related: Led; leading.

To lead with one's chin "leave oneself vulnerable in a contest" (1946) is a figure from boxing. To lead on "entice to advance" is from 1590s. To figuratively lead (someone) by the nose "guide by persuasion" is from 1580s, from draught animals (earlier lead by the sleeve, early 15c.). To lead (someone) a dance "compel through a course of irksome actions" is from 1520s.

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nose (n.)

Middle English nose, from Old English nosu "the nose of the human head, the special organ of breathing and smelling," from Proto-Germanic *nuso- (source also of Old Norse nös, Old Frisian nose, Dutch neus, Old High German nasa, German Nase), from PIE root *nas- "nose."

Used of beaks or snouts of animals from mid-13c.; of any prominent or projecting part supposed to resemble a nose from late 14c. (nose cone in the space rocket sense is from 1949). Meaning "sense of smell" is from mid-14c. Meaning "odor, scent" is from 1894. In Middle English, to have one's spirit in one's nose was to "be impetuous or easily angered" (c. 1400).

Kiv, It could bee no other then his owne manne, that had thrust his nose so farre out of ioynte. ["Barnabe Riche His Farewell to Military Profession," 1581]

To pay through the nose "pay excessively" (1670s) seems to suggest bleeding. Many extended meanings are from the horse-racing sense of "length of a horse's nose," as a measure of distance between two finishers (1908). To turn up one's nose "show disdain, express scorn or contempt" is from 1818 (earlier hold up one's nose, 1570s); a similar notion is expressed in look down one's nose (1907). To say something is under (one's) nose "in plain view, directly in front of one" is from mid-15c. To be as plain as the nose on one's face "very easy to be seen or understood" is from 1590s.

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go-by (n.)
1640s, "an evasion, a leaving behind by artifice," from verbal phrase; see go (v.) + by (adv.). From 1650s as "a passing without notice, intentional disregard." Compare bygone.
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lead-up (n.)
1917, from verbal phrase; see lead (v.1) + up (adv.). To lead up to "prepare gradually for" is from 1861.
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