Bioluminescence is a word made up from two parts: 'bio' means 'life. It is from the Greek 'bios.' The 'luminescence' part is from the Latin 'lume', which means 'lìght.'
So, if you put them together, you have bio= life and lume=light or 'life-light.'
Fireflies, fungi, algae and other plants and animals that light up are therefore, bioluminescent.