Rock bottom

Origin of: Rock bottom

Rock bottom

This is an American colloquial expression from the mid-19th century, used figuratively to mean the lowest possible depth that a state of affairs can sink to. It derives originally from mining where rock bottom was the bedrock or the rock at the bottom of a mining operation beyond which there was no point in continuing. Later it was extended to mean the lowest possible or the very bottom as, for example, in rock bottom prices.