pigeonhole

Short definition from Wiktionary

Noun

1. 1
   One of an array of open compartments for housing pigeons in a dovecote or pigeon loft.
2. 2
   A hole or opening in a door or wall for a pigeon to pass through.
3. 3
   One of an array of open compartments in a desk, set of shelves, etc., used for sorting and/or storing letters, papers, or other items.
4. 4
   One of an array of open compartments in a desk, set of shelves, etc., used for sorting and/or storing letters, papers, or other items: One of an array of open compartments for receiving mail and other messages at a college, office, etc.
5. 5
   A compartment or cubicle in a room or other place, especially one which is (excessively) small.
6. 6
   A small opening for looking or passing things through.
7. 7
   A small opening for looking or passing things through: An opening in a ship for passing equipment such as an oar or rigging through.
8. 8
   A form of stocks with openings for restraining a person's hands or feet; also, one of the openings in the device.
9. 9
   A seat in the top row of the gallery of a theatre.
10. 10
    A notional category or class into which someone or something is placed.
11. 11
    A space between two words that is too wide.

Verb

1. 1
   To construct pigeonholes (noun sense 1 or sense 3.1) in (a place); also, to subdivide (a place) into pigeonholes.
2. 2
   To put (letters, papers, or other items) into pigeonholes or small compartments; also, to arrange or sort (items) by putting into pigeonholes.
3. 3
   To arrange (items) for future reference or use.
4. 4
   To put aside (advice, a proposal, or other matter) for future consideration instead of acting on it immediately; to shelve.
5. 5
   To place (someone or something) into a notional category or class, especially in a way which makes unjustified assumptions or which is restrictive; to categorize, to classify, to label.