Rocky
wiktionary
From Middle English rokki, rokky(“rocky”), [1] from rok, rokke(“rock; a rock or stone; large rock by a coast or in the sea; rocky outcrop on a mountain, cliff; castle, citadel, stronghold”)[and other forms] [2] + -i( suffix forming adjectives). [3]Rok, rokke are derived from:
From rock(“to move back and forth”) + -y(suffix forming adjectives meaning ‘having the quality of’). [5] [6]Rock is derived from Middle English rokken(“to move (something, such as a cradle) back and forth; to move or sway back and forth in an unstable manner; to go”)[…], [7] from Old English roccian(“to rock”), from Proto-Germanic *rukkōną(“to move; to move back and forth, rock”), ultimately from Proto-Indo-European *h₃rewk-(“to dig; to till (soil)”).
From rock(“rock and roll music”) + -y(suffix forming adjectives meaning ‘having the quality of’). [5] [8]
etymonline
rocky (adj.)
"full of rocks," late 15c., rokki, from rock (n.1) + -y (2). Earlier in Middle English as rochi (c. 1300), from French roche. The sense of "unsteady, unstable, tottering" is by 1737, from rock (v.1). The meaning "difficult, hard" is recorded from 1873, and may represent a bit of both.
The Rocky Mountains were 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".
