steadfast adj.

Old English stede "place, position; standing, firmness, stability, fixity," from Proto-Germanic *stadi- (source also of Old Saxon stedi, Old Norse staðr "place, spot; stop, pause; town," Swedish stad, Dutch stede "place," Old High German stat, German Stadt "town," Gothic staþs "place"), from PIE *steti-, suffixed form of root *sta- "to stand, make or be firm." Related to stand.

Now chiefly in compounds or phrases. Meaning "assistance, use, benefit, advantage" is from c. 1300. Meaning "frame on which a bed is laid" is from c. 1400. The German use of Stadt for "town, city" "is a late development from c. 1200 when the term began to replace Burg" [Cambridge Dictionary of English Place-Names]. The Steads was 16c. English for "the Hanseatic cities."

Old English fæst "firmly fixed, steadfast, constant; secure; enclosed, watertight; strong, fortified," probably from Proto-Germanic *fastu- "firm, fast" (source also of Old Frisian fest, Old Norse fastr, Dutch vast, German fest), from PIE root *past- "firm, solid" (source of Sanskrit pastyam "dwelling place").

Meaning "rapid, quick" is from 1550s, from fast (adv.) , in which entry the attempt is made to explain how a root meaning "firm, solid" came variously to yield words for "refrain from eating" (fast (v.)) and "rapid, quick." Of colors, from 1650s; of clocks, from 1840. The sense of "living an unrestrained life, eager in pursuit of pleasure" (usually of women) is from 1746 (fast living is from 1745).

Fast buck recorded from 1947; fast food is first attested 1951. Fast lane is by 1966; the fast track originally was in horse-racing (1934), one that permits maximum speed; figurative sense by 1960s. Fast-forward is by 1948, originally of audio tape.

1520s, "firmly fixed in place or station" (replacing earlier steadfast), from stead + adjectival suffix -y (2), perhaps on model of Middle Dutch, Middle Low German stadig. Old English had stæððig "grave, serious," and stedig "barren," but neither seems to be the direct source of the modern word. Old Norse cognate stoðugr "steady, stable" was closer in sense. As an adverb from c. 1600.

Originally of things; of persons or minds from c. 1600. Meaning "working at an even rate" is first recorded in 1540s. Steady progress is etymologically a contradiction in terms. Steady state first attested 1885; as a cosmological theory (propounded by Bondi, Gold, and Hoyle), it is attested from 1948. Related: Steadily.