Spirit level. See Level. [1913 Webster]

a level, abney level, active air defense, air, air alert, air attache, air attack, air bag, air base, air bed, air bladder, air brake, air brush, air bubble, air built, air castle, air cell, air chamber, air cleaner, air cock, air combat command, air compressor, air condition, air conditioner, air conditioning, air cooling, air corps, air cover, air crew, air current, air cushion, air defense, air division, air drill, air duct, air embolism, air engine, air express, air filter, air flow, air force, air force academy, air force intelligence surveillance and reconnaiss, air force isr, air force officer, air force research laboratory, air force space command, air gap, air gas, air group, air gun, air hammer, air hole, air horn, air hose, air hostess, air jacket, air lane, air letter, air line, air lock, air mail, air marshal, air mass, air mattress, air medal, air mile, air national guard, air out, air passage, air pipe, air plant, air pocket, air poise, air pollution, air potato, air power, air pressure, air pump, air raid, air reconnaissance, air rifle, air sac, air search radar, air shaft, air sick, air sickness, air sock, air space, air speed, air spring, air station, air stove, air terminal, air thermometer, air traffic, air transport, air transportation, air transportation system, air travel, air traveler, air traveller, air unit, air vessel, air wave, air well, amplitude level, background level, biosafety level, biosafety level 1, biosafety level 2, biosafety level 3, biosafety level 4, blood-oxygenation level dependent functional magne, blue air, breath of fresh air, brightness level, calm air, carpenter's level, castle in the air, clear the air, college level, compressed air, current of air, dead air, dumpy level, energy level, flow of air, fuel level, ground level, groundwater level, hole in the air, hot air, in the air, industrial air pollution, intensity level, level, level at, level best, level crossing, level head, level off, light air, liquid air, low level flight, mason's level, naval air warfare center weapons division, noise level, o level, on air, on the level, open air, out of thin air, passive air defense, plumb level, poverty level, pressure level, price level, puff of air, royal air force, sea level, signal level, sound pressure level, special air service, spirit level, split level, support level, surveyor's level, take the air, thin air, threshold level, u. s. air force, united states air force, united states air force academy, up in the air, us air force, us air force academy, walk on air, walking on air, water level, y level