Stricture: An abnormal narrowing of a body passage, especially a tube or a canal. The stricture may be due, for example, to scar tissue or to a tumor. Stricture refers to both the process of narrowing and the narrowed part itself.

A stricture is also anything that closely restrains or limits. Shakespeare used "stricture" in the sense of strictness, as in "A man of stricture and firm abstinence."