ground

The surface of the Earth, as opposed to the sky or water or underground.

“Look, I found a ten dollar bill on the ground!”

Terrain.

Soil, earth.

“The fox escaped from the hounds by going to ground.”

The bottom of a body of water.

Basis, foundation, groundwork, legwork.

(chiefly in the plural) Reason, (epistemic) justification, cause.

“He could not come on grounds of health, or on health grounds.”

Background, context, framework, surroundings.

The area on which a battle is fought, particularly as referring to the area occupied by one side or the other. Often, according to the eventualities, "to give ground" or "to gain ground".

(by extension) Advantage given or gained in any contest; e.g. in football, chess, debate or academic discourse.

The plain surface upon which the figures of an artistic composition are set.

“crimson flowers on a white ground”

In sculpture, a flat surface upon which figures are raised in relief.

In point lace, the net of small meshes upon which the embroidered pattern is applied.

“Brussels ground”

In etching, a gummy substance spread over the surface of a metal to be etched, to prevent the acid from eating except where an opening is made by the needle.

(chiefly in the plural) One of the pieces of wood, flush with the plastering, to which mouldings etc. are attached.

“Grounds are usually put up first and the plastering floated flush with them.”

A soccer stadium.

“Manchester United's ground is known as Old Trafford.”

An electrical conductor connected to the earth, or a large conductor whose electrical potential is taken as zero (such as a steel chassis).

The area of grass on which a match is played (a cricket field); the entire arena in which it is played; the part of the field behind a batsman's popping crease where he can not be run out (hence to make one's ground).

A composition in which the bass, consisting of a few bars of independent notes, is continually repeated to a varying melody.

The tune on which descants are raised; the plain song.

The pit of a theatre.

To connect (an electrical conductor or device) to a ground.

To punish, especially a child or teenager, by forcing him/her to stay at home and/or give up certain privileges.

“Eric, you are grounded until further notice for lying to us about where you were last night!”

To forbid (an aircraft or pilot) to fly.

“Because of the bad weather, all flights were grounded.”

To give a basic education in a particular subject; to instruct in elements or first principles.

“Jim was grounded in maths.”

To hit a ground ball. Compare fly (verb(regular)) and line (verb).

To place something on the ground.

To run aground; to strike the bottom and remain fixed.

“The ship grounded on the bar.”

To found; to fix or set, as on a foundation, reason, or principle; to furnish a ground for; to fix firmly.

To cover with a ground, as a copper plate for etching, or as paper or other materials with a uniform tint as a preparation for ornament.

To improve or focus the mental or emotional state of.

“I ground myself with meditation.”