Also found in: Dictionary.
Lighting provided from a source without reflection from other surfaces. In daylighting, this means that the light has traveled on a straight path from the sky (or the sun) to the point of interest. In electrical lighting, it usually describes an installation of ceiling-mounted or suspended luminaires with mostly downward light-distribution characteristics.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
Lighting in which luminaires distribute 90% to 100% of the emitted light in the direction of the surface to be illuminated, usually in a downward direction.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.