late 14c., in reference to the grammatical case, from Old French genitif or directly from Latin (casus) genitivus "case expressing possession, source, or origin," from genitivus "of or belonging to birth," from genitus, past participle of gignere "to beget, produce" (from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups).
This word was misused by Latin grammarians to render Greek genikē (ptōsis) "the general or generic (case)," expressing race or kind (Greek genikos "belonging to the family"), from genos "family, race, birth, descent," from the same PIE root as the Latin word. As the genitive also is the case of the possessor, and the Romans "were not strong in abstract matters" [Gilbert Murray], the result was some confusion.
The Latin genitivus is a mere blunder, for the Greek word genike could never mean genitivus. Genitivus, if it is meant to express the case of origin or birth, would in Greek have been called gennetike, not genike. Nor does the genitive express the relation of son to father. For though we may say, "the son of the father," we may likewise say, "the father of the son." Genike, in Greek, had a much wider, a much more philosophical meaning. It meant casus generalis, the general case, or rather the case which expresses the genus or kind. This is the real power of the genitive. If I say, "a bird of the water," "of the water" defines the genus to which a certain bird belongs; it refers to the genus of water-birds. [Max Müller, "Lectures on the Science of Language," 1861]
The noun meaning "the genitive case in grammar" is from 1610s.
early 13c., "what befalls one; state of affairs," from Old French cas "an event, happening, situation, quarrel, trial," from Latin casus "a chance, occasion, opportunity; accident, mishap," literally "a falling," from cas-, past-participle stem of cadere "to fall, sink, settle down, decline, perish" (used widely: of the setting of heavenly bodies, the fall of Troy, suicides), from PIE root *kad- "to fall."
The notion is of "that which falls" as "that which happens" (compare befall). From its general nature, the word has taken on widespread extended and transferred meanings. The meaning "instance, example" is from c. 1300. The meaning "actual state of affairs" is from c. 1400. In law, "an instance of litigation" (late 14c.); in medicine, "an instance of a disease" (late 14c.).
The grammatical sense, "one of the forms which make up the inflections of a noun" (late 14c.) also was in Latin, translating Greek ptōsis "declension," literally "a falling." "A noun in the nominative singular ..., or a verb in the present indicative ..., is conceived as standing straight. Then it falls, or is bent, or declines into various positions" [Gilbert Murray, "Greek Studies"]
The U.S. slang meaning "person" (especially one peculiar or remarkable in any way) is from 1848. The meaning "incident or series of events requiring police investigation" is from 1838. In case "in the event" is recorded from mid-14c. Case-history is from 1879, originally medical; case-study "study of a particular case" is from 1879, originally legal; case-law "law as settled by previous court cases" is from 1861.
"receptacle, box, that which encloses or contains," early 14c., from Anglo-French and Old North French casse (Old French chasse "case, reliquary;" Modern French châsse), from Latin capsa "box, repository" (especially for books), from capere "to take, hold" (from PIE root *kap- "to grasp").
The meaning "outer protective covering" is from late 14c. Also used from 1660s with a sense of "frame" (as in staircase, casement). Artillery sense is from 1660s, from case-shot "small projectiles put in cases" (1620s). Its application in the printing trade (first recorded 1580s) to the two shallow wooden trays where compositors keep their types in compartments for easy access led to upper-case for capital letters (1862), so called from its higher position on the compositor's sloped work-table, and lower-case for small letters.
The cases, or receptacles, for the type, which are always in pairs, and termed the 'upper' and the 'lower,' are formed of two oblong wooden frames, divided into compartments or boxes of different dimensions, the upper case containing ninety-eight and the lower fifty-four. In the upper case are placed the capital, small capital, and accented letters, also figures, signs for reference to notes &c.; in the lower case the ordinary running letter, points for punctuation, spaces for separating the words, and quadrats for filling up the short lines. [The Literary Gazette, Jan. 29, 1859]
The meaning "examine, inspect" (usually prior to robbing) is from 1915, American English slang, perhaps from the notion of giving a place a look on all sides. Compare technical case (v.) "cover the outside of a building with a different material" (1707), from case (n.) "external portion of a building" (1670s).
1919, American English, originally a reference to rumors of quadriplegics as a result of catastrophic wounds suffered in World War I (the U.S. military authorities vehemently denied there were any such in its hospitals), from basket (n.) + case (n.2). Probably literal, i.e., stuck in a basket, but basket had colloquial connotations of poverty (begging) and helplessness long before this. The figurative sense of "person emotionally unable to cope" is from 1921.