What does aqueduct mean?
The definition of aqueduct
Aq”ue*duct, n.
Etym: [F. aqueduc, OF. aqueduct (Cotgr.), fr. L. aquaeductus; aquae, gen. of aqua water + ductus a leading, ducere to lead. See Aqua, Duke.]

1 A conductor, conduit, or artificial channel for conveying water, especially one for supplying large cities with water.

Note: The term is also applied to a structure (similar to the ancient aqueducts), for conveying a canal over a river or hollow; more properly called an aqueduct bridge.

2 (Anat.)
A canal or passage; as, the aqueduct of Sylvius, a channel connecting the third and fourth ventricles of the brain.