The bore of a tube such as a hollow needle or catheter.
In the International System of Units, the derived unit of luminous flux; the light that is emitted in a solid angle of one steradian from a source of one candela. Symbol: lm.
The cavity bounded by a plant cell wall.
The cavity or channel within a tube or tubular organ.
A short tube, usually tapering, forming the vent of a hose or pipe.
The nose of an animal; muzzle.
The part of an earbud that accommodates eartips.
A short outlet or inlet pipe projecting from the end or side of a hollow vessel, as a steam-engine cylinder or a steam boiler.