a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance; "the tear duct was obstructed"; "the alimentary canal"; "poison is released through a channel in the snake's fangs"
-A channel for holding and protecting conductors and cables, made of metal or an insulating material, usually circular in cross section like a pipe Also referred to as Conduit
an enclosed conduit for a fluid a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance; "the tear duct was obstructed"; "the alimentary canal"; "poison is released through a channel in the snake's fangs"
Specifically, a tube or passage that confines and conducts a fluid, as a passage for the flow of air to the compressor of a gas-turbine engine, a pipe leading air to a supercharger, etc
A cylindrical or rectangular "tube" used to move air either from exhaust or intake, and for distributing warm air from the heating plant to rooms, or air from a conditioning device or as cold air returns The installation is referred to as "duct work"
A pipe, tube, channel or any other necessary for conveying gases, liquids or solid units from one point to another The term is mostly identified with air-conditioning systems where the transfer of air is necessary This is accomplished through sheet-metal ducts The term is also applicable to under-floor duct systems for conveyance of telephone lines and other electrical conductors
In a glandular context, the manifold created in a compound gland between the tubules of individual simple gland cells and the exit point of the compound gland
A horizontal layer in the atmosphere in which temperature and moisture gradients are such that electromagnetic energy traveling within the layer is bent towards the earth's surface with a curvature equal to or greater than the earth's true curvature A strong temperature inversion and/or moisture lapse rate are necessary for the formation of a duct