rock1

noun

• 1 [mass noun] the solid mineral material forming part of the surface of the earth and other similar planets, exposed on the surface or underlying the soil: the beds of rock are slightly tilted a piece of rock [as modifier]:a spectacular rock arch
• [count noun] a mass of rock projecting above the earth’s surface or out of the sea:there are dangerous rocks around the island
• [count noun] Geology any natural material, hard or soft (e.g. clay), having a distinctive mineral composition.
• (the Rock) informal name for Gibraltar or (Canadian) Newfoundland.

• 2a large piece of rock which has become detached from a cliff or mountain; a boulder:the stream flowed through a jumble of rocks
• North American a stone of any size: the crowd threw a few rocks and dispersed
• [mass noun] British a kind of hard confectionery in the form of cylindrical peppermint-flavoured sticks: a stick of rock
• informal a precious stone, especially a diamond.
• informal a small piece of crack cocaine: crack sells for $20 a rock [mass noun]:the police discovered six ounces of rock in his van
• (rocks) vulgar slang a man’s testicles.

• 3used to refer to someone or something that is extremely strong, reliable, or hard:the Irish scrum has been as solid as a rock

• 4 (usually rocks) (especially with allusion to shipwrecks) a source of danger or destruction:the new system is heading for the rocks

• 5 (rocks) US informal, dated money.