c. 1400, "festering wound or sore on an external soft part of the body," from Old French ulcere, from Vulgar Latin *ulcerem, from Latin ulcus (genitive ulceris) "ulcer, a sore," figuratively "painful subject," from PIE *elkes- "wound" (source also of Greek elkos "a wound, sore, ulcer," Sanskrit arsah "hemorrhoids").

Middle English medical books also used classical ulcus and nativized ulce. The figurative sense of "blot, stain, cause of reproach; corroding or corrupting influence" is by 1590s.

"any soft composition used as an ointment or lubricant," c. 1400, from Latin unguentem "ointment," from stem of unguere "to anoint or smear with ointment."

This is reconstructed to be from PIE root *ongw- "to salve, anoint" (source also of Sanskrit anakti "anoints, smears," Armenian aucanem "I anoint," Old Prussian anctan "butter," Old High German ancho, German anke "butter," Old Irish imb, Welsh ymenyn "butter").

c. 1400, "having power to control fate," in weird sisters, from weird (n.) "force that sets events in motion or determines their course; what is destined to befall one;" from Old English wyrd "fate, chance, fortune; destiny; the Fates." The modern senses developed from weird sisters, not immediately from the Old English word, which is etymologically "that which comes."

It is reconstructed to be from Proto-Germanic *wurthiz (source also of Old Saxon wurd, Old High German wurt "fate," Old Norse urðr "fate, one of the three Norns"), itself reconstructed to be from PIE *wert- "to turn, to wind" (source also of German werden, Old English weorðan "to become"), from root *wer- (2) "to turn, bend." For the sense development from "turning" to "becoming," compare colloquial phrase turn into "become." 

The sense of "uncanny, supernatural" developed from Middle English use of weird sisters for the three Fates, Parcae, or Norns (in Germanic mythology), the goddesses who controlled human destiny. They were portrayed as odd or frightening in appearance, as in "Macbeth" (especially in 18th and 19th century productions).

The modern adjectival use, without sisters, emerged early 19c. Todd's supplement to Johnson (1818) has it as "skilled in witchcraft." Shelley was perhaps the first to use it consistently in print as "supernatural, uncanny":

                In lone and silent hours,

When night makes a weird sound of its own stillness,

["Alastor"]

The weakened meaning "odd-looking, strange, disturbingly different" followed (1820). Also see Macbeth. Related: Weirdly; weirdish; weirdness.

As a verb, "change by witchcraft or sorcery." Earlier to be weirded in Middle English was "be foreordained or predestined."

c. 1400, "engage in business transactions, discuss or arrange terms of a transaction; to vend or sell," from Old French bargaignier "to haggle over the price" (12c., Modern French barguigner), perhaps from Frankish *borganjan "to lend" or some other Germanic source, ultimately from Proto-Germanic *borgan "to pledge, lend, borrow" (source also of Old High German borgen; Old English borgian; from PIE root *bhergh- (1) "to hide, protect;" compare borrow).

Diez and others suggest that the French word comes from Late Latin barca "a barge," because it "carries goods to and fro." There are difficulties with both suggestions. Related: Bargained; bargaining. To bargain for "arrange for beforehand" is from 1801.

c. 1400, "physical, human, mortal," from Old French carnal and directly from Latin carnalis "fleshly, of the flesh," from carnis "of the flesh," genitive of caro "flesh, meat," probably originally "a piece of flesh" (from PIE root *sker- (1) "to cut").

The meaning "sensual, pertaining to the passions and appetites of the flesh" is from early 15c.; that of "worldly, sinful, not spiritual" is from mid-15c.

Carnal suggests that which belongs to the gratification of the animal nature ; it ranges from the merely unspiritual to the sensual. [Century Dictionary]

Carnal knowledge "sexual intercourse" is attested from early 15c. and was in legal use by 1680s. Medieval Latin carnalis meant "natural, of the same blood," a sense sometimes found in Middle English carnal.

c. 1400, "capable of burning or destroying organic tissue, corrosive," from Latin causticus "burning, caustic," from Greek kaustikos "capable of burning; corrosive," from kaustos "combustible; burnt," verbal adjective from kaiein, the Greek word for "to burn" (transitive and intransitive) in all periods, which is of uncertain origin with no certain cognates outside Greek.

The figurative sense of "sarcastic, severely critical" is attested from 1771. As a noun "a caustic substance," early 15c., from the adjective.

c. 1400, "subordinate officer, one given the full power of an officer without holding the office," from Anglo-French deputé, noun use of past-participle of Old French députer "appoint, assign" (14c.), from Late Latin deputare "to destine, allot," in classical Latin "to esteem, consider, consider as," literally "to cut off, prune," from de- "away" (see de-) + putare "to think, count, consider," literally "to cut, prune," from PIE root *pau- (2) "to cut, strike, stamp."

Meaning "person appointed or elected to act in the place of another or others" is from 1769.

"ridicule, mockery, subjection to ridicule or mockery," c. 1400, from Old French derision "derision, mockery" (13c.), from Latin derisionem (nominative derisio) "a laughing to scorn, mockery," noun of action from past-participle stem of deridere "ridicule," from de "down" (see de-) + ridere "to laugh" (see risible).

c. 1400, deschaunt, "a counterpoint added to a given melody," from Anglo-French deschaunt, Old French deschant, from Medieval Latin discantus "refrain, part-song," from Latin dis- "asunder, apart" (see dis-) + cantus "song, a singing; bird-song," from past participle stem of canere "to sing" (from PIE root *kan- "to sing").

The English spelling was partly Latinized in 16c., but it is an exception for its retention of des- in English. It is attested from 1560s in the sense of "the art of composing part-music," also "the upper part or voice." It is attested from 1570s as "a warbled song, a song with various modulations." The transferred sense of "a continued discourse or series of comments on a subject" is recorded from 1590s.

A metaphor taken from musick, where a simple air is made the subject of a composition, and a number of ornamented variations composed upon it. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]

type of berry tree, c. 1400, from earlier ellen, from Old English ellæn, ellærn "elderberry tree," origin unknown, perhaps related to alder, which at any rate might be the source of the unetymological -d-. Common Germanic, cognates: Old Saxon elora, Middle Low German elre, Old High German elira, German Eller, Erle. Related: Elderberry.