Aqueduct
AQ'UEDUCT, noun [Latin aqua, water, and ductus, a pipe or canal, from duco, to lead. See Duke.]
A structure made for conveying water from one place to another over uneven ground; either above or under the surface. It may be either a pipe or a channel. It may be constructed above ground of stone or wood; carried through hills by piercing them, and over valleys, by a structure supported by props or arches. some have been formed with three conduits on the same line, elevated one above another.