1670s, "fall or sink into a muddy place," probably from a Scandinavian source such as Norwegian and Danish slumpe "fall upon," Swedish slumpa; perhaps ultimately of imitative origin. Related: Slumped; slumping.
The word "slump," or "slumped," has too coarse a sound to be used by a lady. [Eliza Leslie, "Miss Leslie's Behaviour Book," Philadelphia, 1839]
Economic sense from 1888.
late 14c., occasioun, "opportunity; grounds for action or feeling; state of affairs that makes something else possible; a happening, occurrence leading to some result," from Old French ochaison, ocasion "cause, reason, excuse, pretext; opportunity" (13c.) or directly from Latin occasionem (nominative occasio) "opportunity, appropriate time," in Late Latin "cause," from occasum, occasus, past participle of occidere "fall down, go down," from ob "down, away" (see ob-) + -cidere, combining form of cadere "to fall" (from PIE root *kad- "to fall"). The notion is of a "falling together," or juncture, of circumstances. The sense of "the time or a time at which something happens" is from 1560s.
late 14c., "an occurrence, incident, event; what comes by chance," from Old French accident (12c.), from Latin accidentem (nominative accidens) "an occurrence; chance; misfortune," noun use of present participle of accidere "happen, fall out, fall upon," from ad "to" (see ad-) + combining form of cadere "to fall," from PIE root *kad- "to fall."
The sense has had a tendency since Latin to extend from "something that happens, an event" to "a mishap, an undesirable event." Latin si quid cui accidat, "if anything should happen to one," was a euphemism for "if one should die." In Middle English the word is met usually in theology (in reference to the material qualities in the sacramental bread and wine), medicine ("something out of the ordinary, disease, injury"), or philosophy ("non-essential characteristic of a thing").
From late 15c. as "the operations of chance." Meaning "an unplanned child" is attested by 1932. Accident-prone is from 1926.
Middle English droppen, from Old English dropian "to fall in drops, fall in small portions or globules, as a liquid." The word is part of a related series of verbs in Proto-Germanic that also yielded Old Saxon driopan, Old Frisian driapa, Dutch druipen, Old High German triufan, German triefen, and in English drip, droop, and obsolete dreep and dripe. Related: Dropped; dropping.
In reference to a solid object, "to fall vertically" from late 14c. The transitive sense "allow to fall" is from mid-14c. To drop in "visit casually" is from c. 1600; drop-in (n.) "a casual visit" is attested by 1819. The notion in drop (someone) a line "write a letter" (1769) is of dropping a message into a letter-box. Exclamation drop dead to express emphatic dislike or scorn is from 1934; as an adjective meaning "stunning, excellent" it is recorded by 1970 (compare killing, etc.).
"becoming obsolete, passing out of use," 1755, from Latin obsolescentum (nominative obsolescens), present participle of obsolescere "fall into disuse" (see obsolete).