This verb can mean different things in different contexts. Here's a common example: If an authority grounds an aircraft or a pilot, this means that they are forbidden to fly. This might happen if the plane is faulty, or if the pilot is considered unfit to fly the plane. A senior officer in the air force might ground a pilot by way of punishment. By extension, if a child or teenager misbehaves, they might be 'grounded' by their parents, meaning that they are not allowed to go out. 'You're grounded!' is a typical comment you might hear from an American parent in a TV show, meaning that the young person has to stay home every evening that week, for example.

In a more technical context, "ground" is used in electrical professions to refer to the "return" or "reference" of a typical electrical circuit. Additionally, as Su. Ki. said above, it has several uses and meanings, depending on the context of it's use. Ground, the verb form can also be used to refer to someone who is "solid" in their philosophy, for example: She is well grounded in math. That would imply that she understands math well and has a good background in math (notice it is used in the compound word...background).

It's a way parents punish their children, by not allowing them to go out, except to school. Example: You're grounded for 2 weeks. Or: If I catch you smoking again, I'll ground you.

'Ground' can also be used as the past tense of 'grind' which means to crush something into smaller pieces. For instance, you might say, 'I have ground the almonds.'