noun

• (uncountable) Terrain.
  "As the terrain-following radar scans the ground ahead of the aircraft the actual clearance height is measured by the radio altimeter."
• (countable) The bottom of a body of water.
• (chiefly in the plural) Reason, (epistemic) justification, cause.
  "You will need to show good grounds for your action."
• (historical) 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".

verb

• (US) To connect (an electrical conductor or device) to a ground.
  "These geomagnetically induced currents (GICs) can become a hazard when they flow through conducting infrastructure, usually entering and exiting networks where equipment is grounded to Earth."
• (Philippines) To electrocute.
• (transitive) To punish, especially a child or teenager, by forcing them to stay at home and/or give up certain privileges.
  "If you don't clean your room, I'll have no choice but to ground you."
• (transitive) To forbid (an aircraft or pilot) to fly.
  "Because of the bad weather, all flights were grounded."