1580s, "to entangle, become entwined confusedly," also "to untangle, disentangle, unwind" (originally with out), from Dutch ravelen "to tangle, fray," rafelen "to unweave," from rafel "frayed thread," which is of uncertain origin. The seemingly contradictory senses of this word (ravel and unravel are both synonyms and antonyms) might be reconciled by its roots in weaving and sewing: as threads become unwoven, they get tangled. The "entangling" meaning is the "more original" sense according to OED. From 1590s in the figurative sense of "make plain or clear;" 1610s as "make a minute and careful investigation." The intransitive sense, of fabric, "become untwisted or disjointed thread from thread" is by 1610s.

short poem in which the initial letters of the lines, taken in order, spell a word or phrase, 1580s, from Medieval Latin acrostichis, from Greek akrostikhis, from akros "at the end, outermost" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + stikhos "line of verse," literally "row, line" (from PIE root *steigh- "to stride, step, rise;" see stair). The second element is properly -stich, but it has been assimilated to words in -ic. As an adjective from 1680s.

"eagle's nest," 1580s (attested in Anglo-Latin from early 13c.), from Old French aire "nest," Medieval Latin area "nest of a bird of prey" (12c.), perhaps from Latin area "level ground, garden bed" [Littré], though some doubt this [Klein]. Another theory connects it to atrium. Formerly spelled eyrie (1660s) on the mistaken assumption that it derived from Middle English ey "egg."

also after-birth, "placenta, etc., expelled from the uterus after birth," 1580s, perhaps based on older, similar Scandinavian compounds; see after + birth (n.). As "a birth after the death or last will of the father," 1875 (translating Latin agnatio in Roman law). Old English had æfterboren (adj.) "posthumous" in reference to birth.

1580s, from Italian bazarra, ultimately from Persian bazar (Pahlavi vacar) "a market," from Old Iranian *vaha-carana "sale, traffic," from suffixed form of PIE root *wes- (1) "to buy, sell" (see venal) + PIE *kwoleno-, suffixed form of root *kwel- (1) "revolve, move round; sojourn, dwell."

1580s, "church of a bishop," from phrase cathedral church (c. 1300) "principal church of a diocese," a phrase partially translating Late Latin ecclesia cathedralis "church of a bishop's seat," from a specific early Christian use of classical Latin cathedra "a teacher or professor's chair," commonly "an easy chair (principally used by ladies)," also metonymically, as in cathedrae molles "luxurious women," from Greek kathedra "chair, seat, bench," also "exalted seat occupied by men of eminent rank or influence," from kata "down" (see cata-) + hedra "seat, base, chair, face of a geometric solid" (from PIE root *sed- (1) "to sit"). The Greek word was used in Old Testament and New Testament translations.

The English word was born an adjective, and attempts to force further adjectivization onto it in 17c. yielded cathedraical (1670s), cathedratic (1660s), cathedratical (1660s), after which the effort seems to have been given up.

"Islamic monk or friar who has taken a vow of poverty and austerity," 1580s, from Turkish dervish, from Persian darvesh, darvish "beggar, poor," hence "religious mendicant;" equivalent of Arabic faqir (see fakir). The "whirling dervishes" are one order among many. Originally dervis; modern spelling is from mid-19c.

1580s, from Greek elephantos, genitive of elephas "elephant" (see elephant) + -iasis "pathological or morbid condition." It refers to two diseases, one characterized by thickening of a body part (E. Arabum), the other, older meaning is "disease characterized by skin resembling an elephant's" (E. Græcorum, also called Egyptian leprosy). In Middle English, elephancy (late 14c.).

1580s, "relief, raised ornament on vessels, etc.," from Latin emblema "inlaid ornamental work," from Greek emblema (genitive emblematos) "an insertion," from emballein "to insert," literally "to throw in," from assimilated form of en "in" (see en- (2)) + ballein "to throw" (from PIE root *gwele- "to throw, reach"). Meaning "allegorical drawing or picture" is from 1730, via sense development in French emblème "symbol" (16c.).

1580s, flibutor "pirate," especially, in history, "West Indian buccaneer of the 17th century" (mainly French, Dutch, and English adventurers), probably ultimately from Dutch vrijbueter (now vrijbuiter) "freebooter," a word which was used of pirates in the West Indies in Spanish (filibustero) and French (flibustier, earlier fribustier) forms. See freebooter.

According to Century Dictionary, the spread of the word is owing to a Dutch work ("De Americaensche Zee-Roovers," 1678) "written by a bucaneer named John Oexmelin, otherwise Exquemelin or Esquemeling, and translated into French and Spanish, and subsequently into English (1684)." Spanish inserted the -i- in the first syllable; French is responsible for the -s-, inserted but not originally pronounced, "a common fact in 17th century F[rench], after the analogy of words in which an original s was retained in spelling, though it had become silent in pronunciation" [Century Dictionary].

In American English, from 1851 in reference to lawless military adventurers from the U.S. who tried to overthrow Central American governments. The major expeditions were those of Narciso Lopez of New Orleans against Cuba (1850-51) and by William Walker of California against the Mexican state of Sonora (1853-54) and against Nicaragua (1855-58).

FILIBUSTERING is a term lately imported from the Spanish, yet destined, it would seem, to occupy an important place in our vocabulary. In its etymological import it is nearly synonymous with piracy. It is commonly employed, however, to denote an idea peculiar to the modern progress, and which may be defined as the right and practice of private war, or the claim of individuals to engage in foreign hostilities aside from, and even in opposition to the government with which they are in political membership. [Harper's New Monthly Magazine, January 1853]

The noun in the legislative sense is not in Bartlett (1859) and seems not to have been in use in U.S. legislative writing before 1865 (filibustering in this sense is from 1861). Probably the extension in sense is because obstructionist legislators "pirated" debate or overthrew the usual order of authority. Originally of the senator who led it; the maneuver itself so called by 1893. Not technically restricted to U.S. Senate, but that's where the strategy works best. [The 1853 use of filibustering by U.S. Rep. Albert G. Brown of Mississippi reported in the Congressional Globe and cited in the OED does not refer to legislative obstruction, but to national policy toward Cuba.]