What is (a) The faculty or power of voluntarily producing light, as in the firefly and glowworm. (b) The light thus produced; luminosity; phosphorescence called?

luminescence — (Zoöl.) (a) The faculty or power of voluntarily producing light, as in the firefly and glowworm. (b) The light thus produced; luminosity; phosphorescence. (Webster's 1913.)

Sources