To hold inside.
To include as a part.
To put constraint upon; to restrain; to confine; to keep within bounds.
I'm so excited, I can hardly contain myself!
(of a set etc.) To have as an element or subset.
A group contains a unique inverse for each of its elements.
To restrain desire; to live in continence or chastity.
Restricted in space.
The brush fire is now contained: if it doesn't jump the lines, it will burn itself out.