Without any grounds to support it; baseless.

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.

The spined loach (Cobitis taenia), weather loach ( Misgurnus fossilis), or other member of the loaches. / The ringed plover, Charadrius hiaticula.

A sheet of waterproof material that is spread on the ground, often beneath a tent, and upon which a person may sit or sleep.

Any of several widely-distributed plants, of the genus Senecio, having yellow, daisylike flowers.

Alternative form of groundsill

Alternative spelling of undergrounder