sake n.1

Middle English sēchen "go in search or quest of; strive for, try to attain," from Old English secan, seocan "search for; pursue, chase; long for, wish for, desire; look for, expect from," influenced by Old Norse soekja, both from Proto-Germanic *sokjanan (source also of Old Saxon sokian, Old Frisian seka, Middle Dutch soekan, Old High German suohhan, German suchen, Gothic sokjan).

This is reconstructed to be from PIE *sag-yo-, from root *sag- "to track down, seek out" (source also of Latin sagire "to perceive quickly or keenly," sagus "presaging, predicting," Old Irish saigim "seek"). The natural modern form of the Anglo-Saxon word, had it not been influenced by Norse, is in beseech. Related: Sought; seeking. 

By late Old English as "ask a question." Seek-sorrow (1580s) was an old term for "a self-tormentor, one who contrives to vex himself." Seek-no-further (or farther) as the name of a type of eating apple is by 1660s.

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.