"sloping timber of a roof," c. 1200, from Old English ræftras (West Saxon), reftras (Mercian), both plural, "a beam, pole, rafter of a building," related to Old Norse raptr "log;" according to Watkins from Proto-Germanic *raf-tra-, from PIE *rap-tro-, from root *rep- "stake, beam."

c. 1200, warant, "protector, defender, one who guards" (a sense now obsolete), from Old North French warant "defender; surety, pledge; justifying evidence" (Old French garant), from Frankish *warand, from Proto-Germanic *war- "to warn, guard, protect" (source also of Old High German werento "guarantor," noun use of present participle of weren "to authorize, warrant;" German gewähren "to grant"). In Watkins this is reconstructed to be from PIE root *wer- (4) "to cover."

It was extended by c. 1300 to "security or assurance provided via a protector; sanction; permission from a superior which protects one from blame or responsibility." Also by c.1300 in reference to letters, etc., serving as validation of authority.

It is attested by 1590s as "justifying reason or grounds for action, belief, etc." From early 14c. in law, "guarantee of a title or right to possession of property." 

Also from early 14c. as "power by official license," and by early 15c. as "written legal document authorizing or commanding some action; a writ." A military warrant officer is one who holds office by warrant (as from a government department), rather than by commission (from a head of state).

"train (an infant or young animal) to forego suckling," c. 1200, wenen, from Old English wenian "to accustom, habituate," from Proto-Germanic *wanjan (source also of Old Norse venja, Dutch wennen, Old High German giwennan, German gewöhnen "to accustom"), reconstructed in Watkins to be from causative form of PIE root *wen- (1) "to desire, strive for."

The sense of "accustom a child to not suckling from the breast" in Old English and early Middle English generally was expressed by gewenian or awenian, which has a sense of "unaccustom" (compare German abgewöhnen, entwöhnen "to wean," literally "to unaccustom"). The modern word might be either (or both) of these verbs with the prefix lost, or it might be wenian in a specialized sense of "accustom to a new diet."

The figurative extension to any pursuit, habit, or desire, "detach or alienate," is from 1520s.

c. 1200, o cros, "in the shape of a cross;" c. 1300, a-croiz, "in a crossed position;" early 14c., acros, "from one side to another;" a contraction of Anglo-French an cros, literally "on cross;" see a- (1) + cross (n.)).

Meaning "on the other side (as a result of crossing)" is from 1750. In crossword puzzle clues from 1924. Spelling acrost, representing a dialectal or vulgar pronunciation, is attested by 1759. Phrase across the board "embracing all categories" (1945) is said to be originally from horse-racing, in reference to a bet of the same amount of money on a horse to win, place, or show. To get (something) across "make (something) understood or appreciated" is by 1913, probably from earlier theater expression get (something) across the footlights, perform it so as to be received by the audience (1894).

c. 1200, amiral, admirail, "Saracen commander or chieftain," from Old French amirail (12c.) "Saracen military commander; any military commander," ultimately from medieval Arabic amir "military commander," probably via Medieval Latin use of the word for "Muslim military leader."

Amiral de la mer "commander of a fleet of ships" is in late 13c. Anglo-French documents. Meaning "highest-ranking naval officer" in English is from early 15c. The extension of the word's meaning from "commander on land" to "commander at sea" likely began in 12c. Sicily with Medieval Latin amiratus and then spread to the continent, but the word also continued to mean "Muslim military commander" in Europe in the Middle Ages. The Arabic word was later Englished as emir.

As amīr is constantly followed by -al- in all such titles, amīr-al- was naturally assumed by Christian writers as a substantive word, and variously Latinized .... [OED]

Also in Old French and Middle English the word was further conformed to familiar patterns as amirauld, amiraunt. The unetymological -d- probably is from influence of Latin ad-mirabilis (see admire). Italian form almiraglio, Spanish almirante are from confusion with Arabic words in al-. As the name of a type of butterfly from 1720, according to OED possibly a corruption of admirable.

c. 1200, aventure, auenture "that which happens by chance, fortune, luck," from Old French aventure (11c.) "chance, accident, occurrence, event, happening," from Latin adventura (res) "(a thing) about to happen," from fem. of adventurus, future participle of advenire "to come to, reach, arrive at." This is from ad "to" (see ad-) + venire "to come" (from a suffixed form of PIE root *gwa- "to go, come").

The meaning developed through "risk; danger" (a trial of one's chances), c. 1300, and "perilous undertaking" (late 14c.) to "novel or exciting incident, remarkable occurrence in one's life" (1560s).

Earlier it also meant "a wonder, a miracle; accounts of marvelous things" (13c.). The -d- was restored in English 15c.-16c.; in French the attempt to restore it at about the same time was rejected. Venture is a 15c. variant. German Abenteuer is a borrowing of the French word, apparently deformed whimsically by influence of Abend "evening."

c. 1200, aduersite "condition of misfortune, hardship, difficulty, distress," from Old French adversite, aversite "adversity, calamity, misfortune; hostility, wickedness, malice" (Modern French adversité), from Latin adversitatem (nominative adversitas) "opposition," from adversus "turned against, hostile" (see adverse).

c. 1200, affeccioun, "desire, inclination, wish, intention;" mid-14c., "an emotion of the mind, passion, lust as opposed to reason;" from Old French afection (12c., Modern French affection) "emotion, inclination, disposition; love, attraction, enthusiasm," from Latin affectionem (nominative affectio) "a relation, disposition; a temporary state; a frame, constitution," noun of state from past-participle stem of afficere "to do something to, act on," from ad "to" (see ad-) + facere (past participle factus) "to make, do" (from PIE root *dhe- "to set, put").

The sense developed in Latin from "disposition" to "good disposition, zealous attachment." In English the sense of "love" is from late 14c. Formally it goes with affect (v.2), but it has absorbed some sense from (v.1). Related: Affections.

c. 1200, "two-wheeled vehicle," usually for one horse and often without springs, from Old Norse kartr or a similar Scandinavian source, akin to and replacing Old English cræt "cart, wagon, chariot," perhaps originally "body of a cart made of wickerwork, hamper" and related to Middle Dutch cratte "woven mat, hamper," Dutch krat "basket," Old English cradol (see cradle (n.)).

Many old allusions are from the cart being used to convey offenders to the gallows (and sometimes serving as a drop for hangings) or for public exposure, especially of lewd women, either in the cart or tied to its tail. Compare tumbrel. To put the cart before the horse in a figurative sense "reverse the natural or proper order of things" is from 1510s in those words; the image in other words dates to mid-14c.: put the plow (sull) before the oxen.

c. 1200, "wasteland, wilderness, barren area," wooded or not, from Old French desert (12c.) "desert, wilderness, wasteland; destruction, ruin" and directly from Late Latin desertum (source of Italian diserto, Old Provençal dezert, Spanish desierto), literally "thing abandoned" (used in Vulgate to translate "wilderness"), noun use of neuter past participle of Latin deserere "forsake" (see desert (v.)).

Sense of "waterless, treeless region of considerable extent" was in Middle English and gradually became the main meaning. Classical Latin indicated this idea with deserta, plural of desertus. Commonly spelled desart in 18c., which is unetymological, but it avoids confusion with the two other senses of the word. 

Every important worker will report what life there is in him. It makes no odds into what seeming deserts the poet is born. Though all his neighbors pronounce it a Sahara, it will be a paradise to him; for the desert which we see is the result of the barrenness of our experience. [Thoreau, Journal, May 6, 1854]