Vent n.
 1. A small aperture; a hole or passage for air or any fluid to escape; as, the vent of a cask; the vent of a mold; a volcanic vent.
    Look, how thy wounds do bleed at many vents.   --Shak.
 Long 't was doubtful, both so closely pent,
 Which first should issue from the narrow vent.   --Pope.
 2. Specifically: --
 (a) Zool. The anal opening of certain invertebrates and fishes; also, the external cloacal opening of reptiles, birds, amphibians, and many fishes.
 (b) Gun. The opening at the breech of a firearm, through which fire is communicated to the powder of the charge; touchhole.
 (c) Steam Boilers Sectional area of the passage for gases divided by the length of the same passage in feet.
 3. Fig.: Opportunity of escape or passage from confinement or privacy; outlet.
 4. Emission; escape; passage to notice or expression; publication; utterance.
    Without the vent of words.   --Milton.
    Thou didst make tolerable vent of thy travel.   --Shak.
 To give vent to, to suffer to escape; to let out; to pour forth; as, to give vent to anger.
 To take vent, to escape; to be made public. [R.]
 Vent feather Zool., one of the anal, or crissal, feathers of a bird.
 Vent field Gun., a flat raised surface around a vent.
 Vent piece. Gun. (a) A bush.  See 4th Bush, n., 2. (b) A breech block.