Hi, yes to ground a child or teenager is to ban them from going out to social events etc. It usually happens if the child has been badly behaved. Grounding can also mean 'keeping someone grounded' meaning to ensure they have a level head, a balanced view etc.

It varies from family to family and situation to situation. A child who did something slightly naughty might be grounded for a shorter time or from fewer activities/hobbies while a child who did something really awful might be grounded from everything for a really long time. A parent will say something like "You're grounded. No video games, tv, or telephone for a month." or "Mohamed is grounded from anything but school and home this week." If someone says that they're grounded, then they have some restrictions on them - but you'd have to ask to find what exactly is and isn't being allowed.