At work, Peggy was forced to deal with a rocky relationship with art director Stan Rizzo (Jay R. Ferguson).
In our Solar System, only smaller, rocky planets orbit within the habitable zone.
And, hey, the transtastic number was good practice for the rocky Horror tribute episode, airing October 26.
"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".