This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

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n. An opening, such as a hole, gap, or slit.

n. A usually adjustable opening in an optical instrument, such as a camera or telescope, that limits the amount of light passing through a lens or onto a mirror.

n. The diameter of such an opening, often expressed as an f-number.

n. The diameter of the objective of a telescope.

n. An opening; an open space; a gap, cleft, or chasm; a passage perforated; a hole; as, an aperture in a wall.

n. Something which restricts the diameter of the light path through one plane in an optical system.

n. The diameter of the aperture (in the sense above) which restricts the width of the light path through the whole system. For a telescope, this is the diameter of the objective lens. e.g. a telescope may have a 100 cm aperture.

n. The (typically) large-diameter antenna used for receiving and transmitting radio frequency energy containing the data used in communication satellites, especially in the geostationary belt. For a comsat, this is typically a large reflective dish antenna; sometimes called an array.

n. The maximum angle between the two generatrices.

n. The act of opening.

n. An opening; an open space; a gap, cleft, or chasm; a passage perforated; a hole.

n. The diameter of the exposed part of the object glass of a telescope or other optical instrument.

n. The act of opening out or unfolding.

n. An opening; a hole, orifice, gap, cleft, or chasm; a passage or perforation; any direct way for ingress or egress.

n. In geometry, the space between two intersecting right lines.

n. In optics, the diameter of the exposed part of the object-glass in a telescope or other optical instrument.

n. a device that controls amount of light admitted

n. an man-made opening; usually small

n. a natural opening in something

"In retailing the size of the aperture is often used to provide shoppers with clues about what is in a store."

regulator   

absolute aperture    relative aperture of a lens    aperture-sight    pedal aperture    abdominal apertures    branchial aperture   

aperient   

opening    hole   

opening    orifice    slit    fissure    gash    diameter    archway    lens    cavity    pane