■ noun
1》 a small recess for a domestic pigeon to nest in.
2》 each of a set of small compartments where letters or messages may be left for individuals.
3》 a category, especially an overly restrictive one, to which someone or something is assigned.
■ verb
1》 assign to a particular category, especially an overly restrictive one.
2》 deposit (a document) in a ~.