CAT, aerospace, aerosphere, air duct, air passage, air pocket, air shaft, air tube, airspace, airway, armhole, blowhole, breathing hole, bullet-hole, bump, bunghole, ceiling, cringle, crosswind, deadeye, empty space, eye, eyelet, favorable wind, fog, front, gasket, grommet, guide, head wind, high-pressure area, hole, ionosphere, jetstream, keyhole, knothole, loop, loophole, louver, louverwork, low-pressure area, manhole, mousehole, naris, nostril, overcast, peephole, pigeonhole, pinhole, placket, placket hole, pocket, porthole, punch-hole, roughness, shaft, soup, space, spilehole, spiracle, stratosphere, substratosphere, tail wind, tap, touchhole, transom, tropopause, troposphere, trough, turbulence, vent, ventage, venthole, ventiduct, ventilating shaft, ventilator, visibility, visibility zero, wind tunnel