pigeonhole

One of an array of compartments for housing pigeons.

One of an array of compartments for receiving mail and other messages at a college, office, etc.

One of an array of compartments for storing scrolls at a library.

A similar compartment in a desk, used for sorting and storing papers.

To categorize; especially to limit or be limited to a particular category, role, etc.

To put aside, to not act on (proposals, suggestions, advice).