earlier also feaver, late Old English fefor, fefer "fever, temperature of the body higher than normal," from Latin febris "fever," related to fovere "to warm, heat," which is probably from PIE root *dhegh- "burn" (source also of Gothic dags, Old English dæg "day," originally "the heat;" Greek tephra "ashes;" Lithuanian dāgas "heat," Old Prussian dagis "summer;" Middle Irish daig "fire"); but some suggest a reduplication of a root represented by Sanskrit *bhur- "to be restless."

The Latin word was adopted into most of the Germanic languages (German Fieber, Swedish feber, Danish feber), but not Dutch. English spelling was influenced by Old French fievre.

An alternative word for "fever" was Old English hrið, hriðing (which is cognate with Old High German hritto, Irish crith, Welsh cryd, Lithuanian skriečiù, skriesti); Latin febris also was glossed by bryneadl. The extended sense of "intense nervous excitement" is from 1580s. Also as a verb in Old English, feferian.

late 14c., "by day; on or in the day or time," with adverbial genitive -s from earlier aday (mid-13c.), prepositional phrase used as an adverb, from a- (1) "on, on each" + day (n.). The genitive ending now is regarded as an accusative plural.

late 14c., from Old English byrddæg, "anniversary or celebration of one's birth" (at first usually a king or saint); see birth (n.) + day. The meaning "day on which one is born" is from 1570s. Birthnight is attested from 1620s.

German federal council, 1879, from German Bundestag, from genitive of Bund "league, confederacy, association" (related to English band (n.2) and bind (v.)) + tag, literally "day;" as a verb, tagen, "to sit in conference" (see day; also compare adjourn). Hence also Bundesrat "federal council of the German empire" (1872), from rat, rath "council" (see rathskeller).

"stop working, cease from effort," by 1902, from earlier use in reference to regarding labor for part of a day as equivalent to a day's work for purpose of pay, etc.

"Let's see," said the captain: "you were to have half a dollar a day; we'll call it a day, though it ain't sundown yet. That's fifty cents for you." [from story in Pacific Christian Advocate, May 31, 1899]

To call it a day's labor is by 1877. To close the school at noon and call it a day (of a teacher) is attested in 1875. See call (v.) + day (n.). To call it a night "go to bed" is by 1912.

"happening or being every day," mid-15c.; see day + -ly (1). Compare Old English dglic, a form found in compounds: twadglic "happening once in two days," reodglic "happening once in three days." The more usual Old English adjective was dghwamlic (also dgehwelc), which became Middle English daiwhamlich. Cognate with German tglich.

As an adverb, "every day, day by day," early 15c. (the Old English adverb was dghwamlice. As a noun, "a daily newspaper," by 1832.

common wildflower of Europe, growing in pastures and on mountainsides and cultivated in gardens, c. 1300, daiseie, from Old English dægesege, from dæges eage "day's eye;" see day (n.) + eye (n.). So called because the petals open at dawn and close at dusk. In Medieval Latin it was solis oculus "sun's eye." The use of dais eye for "the sun" is attested from early 15c.

Applied to similar plants in America, Australia, New Zealand. As a female proper name said to have been originally a pet form of Margaret (q.v.). Slang sense of "anything pretty, charming, or excellent" is by 1757.

Daisy-cutter first attested 1791, originally "a trotting horse," especially one that trots with low steps; later of cricket (1889) and baseball hits that skim along the ground. Daisy-chain is used in various figurative senses from 1856; the "group sex" sense is attested by 1941. Daisy-wheel for a removable printing unit in the form of a flat wheel is attested by 1974.

To push up daisies "be dead and buried" is from World War I:

"Pushing up the daisies now," said a soldier of his dead comrade. [The American Florist, vol. xlviii, March 31, 1917]

But association of the dead and the daisies is in "Ingoldsby" (1842):

Be kind to those dear little folks

    When our toes are turn'd up to the daisies!

also daycare, day-care, "care and supervision of young children during the day," especially on behalf of working parents, by 1943, American English, from day + care (n.). Early references are to care for children of women working national defense industry jobs. For an earlier word, see baby-farmer.

also daybook, "book for recording events and transactions of the day," 1570s, from day (n.) + book (n.).

"dawn, first appearance of light in the morning," 1520s, from day + break (n.).