early 13c., "of or pertaining to the head," from Old French capital, from Latin capitalis "of the head," hence "capital, chief, first," from caput (genitive capitis) "head" (from PIE root *kaput- "head"). The meaning "main, principal, chief, dominant, first in importance" is from early 15c. in English. The modern informal sense of "excellent, first-rate" is by 1754 (as an exclamation of approval, OED's first example is 1875), perhaps from earlier use of the word in reference to ships, "first-rate, powerful enough to be in the line of battle," attested from 1650s, fallen into disuse after 1918. Related: Capitally.
A capital letter "upper-case latter," of larger face and differing more or less in form (late 14c.) is so called because it stands at the "head" of a sentence or word. Capital gain is recorded from 1921. Capital goods is recorded from 1899.
A capital crime or offense (1520s) is one that involves the penalty of death and thus affects the life or "head" (capital had a sense of "deadly, mortal" from late 14c. in English, as it did earlier in Latin). The felt connection between "head" and "life, mortality" also existed in Old English: as in heafodgilt "deadly sin, capital offense," heafdes þolian "to forfeit life." Capital punishment was in Blackstone (1765) and classical Latin capitis poena.
Old English suð "southward, to the south, southern, in the south," from Proto-Germanic *sunthaz, perhaps literally "sun-side" (source also of Old Saxon, Old Frisian suth "southward, in the south," Middle Dutch suut, Dutch zuid, German Süden), and related to base of *sunnon "sun" (from PIE root *sawel- "the sun"). Old French sur, sud (French sud), Spanish sur, sud are loan-words from Germanic, perhaps from Old Norse suðr.
As an adjective from c. 1300; as a noun, "one of the four cardinal points," also "southern region of a country," both late 13c. The Southern states of the U.S. have been collectively called The South since 1779 (in early use this often referred only to Georgia and South Carolina). South country in Britain means the part below the Tweed, in England the part below the Wash, and in Scotland the part below the Forth. South Sea meant "the Mediterranean" (late 14c.) and "the English Channel" (early 15c.) before it came to mean (in plural) "the South Pacific Ocean" (1520s) and it was frequent for "the Pacific Ocean" generally in U.S. in early 19c. (Thoreau, J.Q. Adams).
"head of a column or pillar," late 13c., from Anglo-French capitel, Old French chapitel (Modern French chapiteau), or directly from Latin capitellum "head of a column or pillar," literally "little head," diminutive of caput "head" (from PIE root *kaput- "head").
1610s, "a person's wealth," from Medieval Latin capitale "stock, property," noun use of neuter of Latin capitalis "capital, chief, first" (see capital (adj.)). From 1640s as "the wealth employed in carrying on a particular business," then, in a broader sense in political economy, "that part of the produce of industry which is available for further production" (1793).
[The term capital] made its first appearance in medieval Latin as an adjective capitalis (from caput, head) modifying the word pars, to designate the principal sum of a money loan. The principal part of a loan was contrasted with the "usury"—later called interest—the payment made to the lender in addition to the return of the sum lent. This usage, unknown to classical Latin, had become common by the thirteenth century and possibly had begun as early as 1100 A.D., in the first chartered towns of Europe. [Frank A. Fetter, "Reformulation of the Concepts of Capital and Income in Economics and Accounting," 1937, in "Capital, Interest, & Rent," 1977]
Also see cattle, and compare sense development of fee, and pecuniary. Middle English had chief money "principal fund" (mid-14c.). The noun use of the adjective in classical Latin meant "a capital crime."
South Korean capital, from Korean soul, literally "capital." It was the national capital from 1392 until Japanese annexation in 1910.
city in China, literally "southern capital," from Chinese nan "south" + jing "capital."
1853, from Slav + Serbo-Croatian jugo- "south," combining form of jug "south, south wind, noon," from Old Church Slavonic jugu "south, south wind, noon."
1947, American English, "officer in charge," from Japanese hancho "group leader," from han "corps, squad" + cho "head, chief." Picked up by U.S. servicemen in Japan and Korea, 1947-1953.