Synonyms to peephole

air hole, 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, 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, beacon, AM transmitter, FM transmitter, Klaxon, Mayday, RT transmitter, Roman candle, SOS, Texas tower, Very flare, aid to navigation, air-raid alarm, airport beacon, airway beacon, alarm, alarm bell, alarm clock, alarm signal, alarum, alert, all clear, amateur transmitter, amber light, anchor lig