mid-14c., "narrow, confined space or place," specifically of bodies of water from late 14c., from Old French estreit, estrait "narrow part, pass, defile, narrow passage of water," noun use of adjective (see strait (adj.)). Sense of "difficulty, plight" (usually straits) first recorded 1540s. Strait and narrow "conventional or wisely limited way of life" is recorded from mid-14c. (compare straight (adj.2)).
c. 1600, "too narrow;" 1716, "reduced to hardship;" past-participle adjective from strait (v.). Phrase straitened circumstances recorded from 1766.
"conventional," especially "heterosexual," 1941, a secondary sense evolved from straight (adj.1), probably suggested by straight and narrow path "course of conventional morality and law-abiding behavior," which is based on a misreading of Matthew vii.14 (where the gate is actually strait), and the other influence seems to be from strait-laced.
Canadian French province, from Micmac (Algonquian) /kepe:k/ "strait, narrows." Related: Quebecois (n. and adj.), from French Québecois.
strait between the Aegean Sea and the Sea of Marmara, separating Europe from Asia, the classical Hellespont, probably from Dardanus (Greek Dardanos), name of an ancient city near Troy, on the Asia side of the strait, home of the Dardani, a people-name said to be from a mythical founder Dardanus, but this is likely folk-etymology. Related: Dardanian.
"narrow channel of water," c. 1300, from Old Norse sund "a strait, swimming," or from cognate Old English sund "act of swimming, stretch of water one can swim across, a strait of the sea," both from Proto-Germanic *sundam-, from *swum-to-, suffixed form of Germanic root *swem- "to move, stir, swim" (see swim (v.)).