noun:

1. The plain surface upon which the figures of an artistic composition are set.
2. A soccer stadium.
3. A composition in which the bass, consisting of a few bars of independent notes, is continually repeated to a varying melody.
4. The bottom of a body of water.
5. The net of small meshes upon which the embroidered pattern is applied.
6. Terrain.
7. A flat surface upon which figures are raised in relief.
8. One of the pieces of wood, flush with the plastering, to which mouldings etc. are attached.
9. Soil, earth.
10. Advantage given or gained in any contest; e.g. in football, chess, debate or academic discourse.
11. 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).
12. Background, context, framework, surroundings.
13. 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".
14. Basis, foundation, groundwork, legwork.
15. The surface of the Earth, as opposed to the sky or water or underground.
16. An electrical conductor connected to the earth, or a large conductor whose electrical potential is taken as zero (such as a steel chassis).
17. The tune on which descants are raised; the plain song.
18. 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.
19. Reason, (epistemic) justification, cause.
20. The pit of a theatre.

verb:

1. 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.
2. To punish, especially a child or teenager, by forcing him/her to stay at home and/or give up certain privileges.
3. To hit a ground ball. Compare fly (verb(regular)) and line.
4. Simple past tense and past participle of grind.
5. To give a basic education in a particular subject; to instruct in elements or first principles.
6. To improve or focus the mental or emotional state of.
7. To place something on the ground.
8. To run aground; to strike the bottom and remain fixed.
9. To found; to fix or set, as on a foundation, reason, or principle; to furnish a ground for; to fix firmly.
10. To connect (an electrical conductor or device) to a ground.
11. To forbid (an aircraft or pilot) to fly.

adjective:

1. Crushed, or reduced to small particles.
2. Processed by grinding.