An "overprotective" person tries too hard to keep someone safe. Here are some examples of things that an "overprotective" person might do:

• make their teenage children be home by 9:30 in the evening.
• buy only organic food for their family.
• print out copies of all of your travel information for you when you're going on a trip.

You say that a person is "overprotective of (someone)":

She's overprotective of her children.

The people who are "overprotective" of someone are usually their parents. Sometimes a grandparent, aunt, uncle, or older sibling might also be overprotective.