(formerly) a lighting unit for spotlighting the front of the stage, producing illumination by means of a flame of mixed gases directed at a cylinder of lime and having a special lens for concentrating the light in a strong beam.
b.
the light so produced.
c.
Chiefly British. a lighting unit, esp. a spotlight.
2.
the center of public attention, interest, observation, or notoriety: He seems fond of the limelight.
1826, popular name for Drummond light, a brilliant light created by the incandescence of lime (1), adopted for lighthouses and later for the Victorian stage, where it illuminated the principal actors, hence the figurative sense of "on stage, at the center of attention" (1877).
[lahym-lahyt] 
