Completely filled in or covered; completely closed up (as a car with all the windows up); plugged (as a hole, leak, opening).
This child's body is completely covered with sores.
To fill in; to plug up; to close or cover s.t. (so it is tight fitting i.e. there are no holes, gaps, cracks, spaces, etc. [The -an and -un imperatives are sometimes interchanged].
Who filled in the hole in that cement?
Make it tight fitting when you put a cover on that tank.