troffer

plural troffers

1. A rectangular, trough-shaped light fixture, typically for mounting in or on a ceiling to light the area below, and usually containing two or three fluorescent bulbs.

   Each fluorescent troffer in the room contained three lamps and two ballasts.

   1 more example

   Flexibility for troffer systems may be planned in the original layout by coordinating the over-all ceiling pattern with the modular size of troffer.

   1956, National Research Council, Design for environment: floor, ceilings, and service systems in multi-story buildings, page 36