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

present participle of ground

plural of grounding

(of a missile) Fired from the ground at a target on the ground.

The surface of the Earth, as opposed to the sky or water or underground. / (uncountable) Terrain. / Soil, earth. / (countable) The bottom of a body of water. / Basis, foundation, groundwork, legwork.

(US) To connect (an electrical conductor or device) to a ground. / (transitive) To punish, especially a child or teenager, by forcing them to stay at home and/or give up certain privileges.

simple past tense and past participle of grind

Crushed, or reduced to small particles. / Processed by grinding.

plural of ground

Third-person singular simple present indicative form of ground