ground

1. The surface of the Earth, as opposed to the sky or water or underground. (countable, uncountable) · Look, I found a ten dollar bill on the ground!
2. Terrain. (uncountable)
3. Soil, earth. (countable, uncountable) · The worm crawls through the ground.
4. The bottom of a body of water. (countable)
5. Basis, foundation, groundwork, legwork. (countable, uncountable)
6. Reason, (epistemic) justification, cause. (countable, uncountable) · You will need to show good grounds for your action.· He could not come on grounds of health, or on health grounds.
7. Background, context, framework, surroundings. (countable, uncountable)
8. 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". (countable, uncountable)

Plural grounds