Technology / Aviation / Ceiling: (1) The heights above the earth's surface of the lowest layer of clouds or obscuring phenomena that is reported as 'broken,' 'overcast,' or 'obscuration,' and not classified as 'thin' or 'partial'. (2) The maximum height above sea level in STANDARD AIR attainable by an aircraft under given conditions—see ABSOLUTE CEILING, SERVICE CEILING.
Business / Construction / Ceiling Joist: One of a series of parallel framing members used to support ceiling loads and supported in turn by larger beams, girders or bearing walls. Also called roof joists. MORE
Science / Weather / Variable Ceiling: Occurs when the height of a ceiling layer increases and decreases rapidly, The ascribed height is the average of all the varying values. MORE