an English notion of a stereotypical French oath, 1869, from French sacré bleu, literally "holy blue," a euphemism for sacré Dieu (1768), "holy God." From Old French sacrer, from Latin sacrare "to make or declare sacred" (see sacred). Such things are never idiomatic. In an old French-language comic set in the U.S. Wild West, the angry cowboys say "Bloody Hell!"

"a tidal river," 1650s; see salt (n. ) + river. as a proper name, it was used early 19c. with reference to backwoods inhabitants of the U.S., especially those of Kentucky (there is a Salt River in the Bluegrass region of the state; the river is not salty, but salt manufactured from salt licks in the area was shipped down the river). The U.S. political slang phrase to row (someone) up Salt River "send (someone) to political defeat" probably owes its origin to this geographical reference, as the first attested use (1828) is in a Kentucky context. The phrase may also refer to the salt of tears.

"the sea; naturally occurring salt water," late Old English sealtera watera. As an adjective from 1520s, "inhabiting salt water or the sea." Salt-water taffy attested by 1886; so called because it originally was sold at seashore resorts, especially Atlantic City, N.J. (see taffy).

common name of a small wading bird that runs along the sand and utters a piping note, 1670s, from sand (n.) + piper.

1773 (as St. A Claus, in "New York Gazette"), American English, in reference to the customs of the old Dutch colony of New York, from dialectal Dutch Sante Klaas, from Middle Dutch Sinter Niklaas "Saint Nicholas," bishop of Asia Minor who became a patron saint for children. Now a worldwide phenomenon (Japanese santakurosu). Father Christmas is attested from 1650s.

1929 (in advertisements for "Air Wonder Stories" magazine), though there is an isolated use from 1851. See science + fiction. Earlier in same sense was scientifiction (by 1926). Abbreviated form sci-fi is by 1955. 

1909 as a heraldic animal, 1964 as a U.S. proprietary name for brine shrimp (Artemia salina), which had been raised as food for aquarium fish but were marketed as pets by U.S. inventor Harold von Braunhut (1926-2003), who also invented "X-Ray Specs" and popularized pet hermit crabs. He began marketing them in comic book advertisements in 1960 as "Instant Life," and changed the name to Sea Monkeys in 1964, so called for their long tails.

late 14c., from Latin secundum naturam "according to nature" (Augustine, Macrobius, etc.), literally "following nature" (see second (adj.)). A term from medieval Aristotelian philosophy, contrasted to phenomena that were super naturam ("above nature," such as God's grace), extra naturam ("outside nature"), supra naturam ("beyond nature," such as miracles), contra naturam "against nature," etc.

Latin, "always the same;" from semper "always, ever" (see semper-) + idem "the same" (see idem).

verbal phrase; see set (v.) + off (adv.). From 1590s as "make prominent by contrast," 1610s as "adorn." Intransitive sense of "start on or as on a journey" is from 1774. Meaning "separate from contect" (in typography) is from 1824; sense of "ignite, discharge, cause to explode" is from 1810.