blood

Etymology

From Middle English blood, from Old English blōd, from Proto-West Germanic *blōd, from Proto-Germanic *blōþą, possibly from Proto-Indo-European *bʰel- ("to swell") + -ó- (thematic vowel) + -to (nominalizer), i.e. "that which bursts out". Cognate with Saterland Frisian Bloud, West Frisian bloed, Dutch bloed, German Blut, Danish, Swedish and Norwegian blod.

noun

1. A vital liquid flowing in the bodies of many types of animals that usually conveys nutrients and oxygen. In vertebrates, it is colored red by hemoglobin, is conveyed by arteries and veins, is pumped by the heart and is usually generated in bone marrow.
   The cultists gathered around a chalice of blood.
   The case was that of a murder. It had an element of mystery about it, however, which was puzzling the authorities. A turban and loincloth soaked in blood had been found; also a staff. 1927, F. E. Penny, chapter 4, in Pulling the Strings
   An artificial kidney these days still means a refrigerator-sized dialysis machine. Such devices mimic the way real kidneys cleanse blood and eject impurities and surplus water as urine. 2013-06-01, “A better waterworks”, in The Economist, volume 407, number 8838, page 5 (Technology Quarterly)
2. A family relationship due to birth, such as that between siblings; contrasted with relationships due to marriage or adoption. (See blood relative, blood relation.)
   a friend of our own blood 1690, Edmund Waller, The Maid's Tragedy Altered
3. (historical) One of the four humours in the human body.
4. (medicine, countable) A blood test or blood sample.
   When I got Bilbo to their surgery the vet took Bilbo in for tests. […] His bloods showed nothing wrong at all. 2016, Steve Jamieson, Bilbo the Lifeguard Dog
5. The sap or juice which flows in or from plants.
   It is no tautology to call the blood of the grape red or purple, because the juice of that fruit was sometimes white and sometimes black or dark. The arterial blood of our bodies is red, but the venous is called "black blood." 1841, Benjamin Parsons, Anti-Bacchus, page 95
   Disbudding is merely a species of pruning, and should be done as soon as the lateral buds begin to develop on the cane. It diverts the flow of the plant's blood from many buds into one or a few, thus increasing the size of the flower, … 1901, Levi Leslie Lamborn, American Carnation Culture, fourth edition, page 57
   Look at a leaf. On it are many little raised lines which reach out to all parts of the leaf and back to the stem and twig. These are "veins," full of the tree's blood. It is white and looks very much like water; … 1916, John Gordon Dorrance, The Story of the Forest, page 44
6. (poetic) The juice of anything, especially if red.
7. Temper of mind; disposition; mood
   There was some little undefinable coolness between old General Chattesworth and Devereux. He admired the young fellow, and he liked good blood in his corps, but somehow he was glad when he thought he was likely to go. When old Bligh, of the Magazine, commended the handsome young dog's good looks, the general would grow grave all at once […] 1863, Sheridan Le Fanu, The House by the Churchyard
8. (obsolete) A lively, showy man; a rake; a dandy.
9. A blood horse, one of good pedigree.
10. (figurative) Bloodshed.
    They came looking for blood.
    Under Henry III. Amboise ceased to be a slaughter-house, as in the preceding reign, but it remained a sort of state prison. It is related that Anne d'Este of Ferrara, wife of Duc de Guise, while assisting once at a series of executions out of the windows of the castle with Catherine de Medicis, suddenly overcome by the horror of the spectacle, turned away, exclaiming passionately, "Ah Madame! how all this blood calls out for blood! what vengeance is being prepared! May God have pity on your sons and on mine!" 1873, The Monthly Packet of Evening Readings for Members of the English Church, page 31
    He watched out for the men in his unit, for the one woman who had saved them so many years ago when they were still raw teens out for blood and revenge on the world, and he watched out for anyone else they stumbled across in their lives that needed protection. 2007, Christine Feehan, Deadly Game, Penguin, page 55
    The standard assessment suggests that as the munera became purely a spectacle, they became more murderous because the public wanted to see blood. That the people of Rome were able to indulge this degenerate desire was merely due to the degraded status of the professional gladiator. 2010, Alison Futrell, Blood in the Arena: The Spectacle of Roman Power, University of Texas Press, page 169
11. Alternative letter-case form of Blood (“member of a certain gang”)
12. (especially African-American Vernacular) A friend or acquaintance, especially one who is black and male.
13. (UK, MLE, slang) Alternative form of blud (“Informal address to a male.”)
    Blood I swear she just gave man extra chicken? Two fat pieces of chicken. 2017, Joseph Barnes Phillips, Big Foot ...and Tiny Little Heartstrings

verb

1. (transitive) To cause something to be covered with blood; to bloody.
2. (medicine, historical) To let blood (from); to bleed.
   Mr Western, who imputed these symptoms in his daughter to her fall, advised her to be presently blooded by way of prevention. 1749, Henry Fielding, Tom Jones, Folio Society, published 1973, page 121
   She had been blooded, he said, 12 times in this last fortnight, and had lost 75 ounces of blood, besides undergoing blistering,and other discipline. 1785, Frances Burney, Journals & Letters, Penguin, published 2001, page 212
3. (transitive) To initiate into warfare or a blood sport, traditionally by smearing with the blood of the first kill witnessed.