1. An artificial channel for the conveyance or conducting of water from place to place; a conduit; especially, an elevated structure of masonry used for this purpose.
2. A bridgelike structure that carries a water conduit or canal across a valley or over a river.
3. In physiology, a name given to several small canals through which liquids pass, primarily in the heads of mammals.
4. A passage or channel in a body structure or organ.