Alternative form of groundwater

Used other than figuratively or idiomatically: see in, groove.

(chemistry) Any of many effects in organic chemistry in which the course of a reaction, or its rate, is affected by the presence of a neighbouring functional group; anchimeric assistance

(intransitive, especially of an animal, chiefly UK) To escape into a burrow, hole, etc. when being hunted.

Fundamental knowledge or background in a field or discipline. / The return to a fully conscious state after a psychedelic experience.

present participle of ground

An annual festival held in Canada and the USA on February 2 in which the arrival time of the spring season is predicted by whether or not a certain groundhog can see its shadow.

(informal) A situation in which events appear to be repeating themselves in a cyclical fashion.

(informal) To live out a situation in which events appear to be repeating themselves in a cyclical fashion.

(nautical, surfing) A broad undulation of the open ocean, often as the result of a distant disturbance. / (by extension) A broadly-based shifting of public opinion.