to keep someone or something enclosed within a space or scope, to restrict them to certain limits such as quantity or time, often preventing or forbidding them from leaving;
e.g. We must confine ourselves to this small apartment until we find other lodgings.
(noun)
the enclosing boundaries or borders of a space that pose a restriction to movement or freedom beyond (usually used as "confines");
e.g. You cannot leave the confines of this room without permission.
(noun)
the restrictions or limitations posed by something abstract, especially a situation or field of study (often used as "confines");
e.g. The topic is outside the confines of our discussion.