"large, loose sash worn as a belt," 1610s, from Hindi kamarband "loin band," from Persian kamar "waist" + band "something that ties," from Avestan banda- "bond, fetter," from PIE root *bhendh- "to bind."
long, loose, fur-skinned mantle formerly worn by Native Americans, 1640s, originally matchco, probably a native word (compare Ojibwa majigoode "petticoat, woman's dress"), altered by influence of coat (n.).
early 14c., "cessation" (of pain, grief, etc.), from slack (adj.). Meaning "a cessation of flow in a current or tide" is from 1756; that of "still stretch of a river" is from 1825. Meaning "loose part or end" (of a rope, sail, etc.) is from 1794; hence figurative senses in take up the slack (1930 figuratively) and slang cut (someone) some slack (1968). Meaning "quiet period, lull" is from 1851. Slacks "loose trousers" first recorded 1824, originally military.
In English, of rules, discipline, etc., from mid-15c. Related: Laxly; laxness. A transposed Vulgar Latin form yielded Old French lasche, French lâche. The laxists, though they formed no avowed school, were nonetheless condemned by Innocent XI in 1679.