"full of rocks," c.1400, from rock, n.1 + -y(2); "unsteady," 1737, from rock, v.1. Meaning "difficult, hard" is recorded from 1873, and may represent a bit of both.The Rocky Mountains so called by 1802, translating French Montagnes Rocheuses, first applied to the Canadian Rockies. "The name is not directly self-descriptive but is an approximate translation of the name of the former Native American people here known as the Assiniboin .... The mountains are in fact not noticeably rocky" [Room]. Bright notes that "These Indians were called /assiniipwaan/, lit. 'stone Sioux', by their Cree (Algonkian) neighbors".