a. Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.
b. Electromagnetic radiation of any wavelength.
2. The sensation of perceiving light; brightness: a sudden light that made me blink.
a. A source of light, especially a lamp, a lantern, or an electric lighting fixture: Turn out the lights when you leave.
b. The illumination derived from a source of light: by the light of the moon.
c. The particular quantity or quality of such illumination: moved the lamp closer to get better light.
d. The pathway or route of such illumination to a person: You’re standing in his light.
4. A mechanical device that uses illumination as a signal or warning, especially a beacon or traffic signal.
b. Dawn; daybreak.
6. Something, such as a window, that admits illumination.
7. Architecture One of two or more openings in a window divided by a mullion or mullions.
8. A source of fire, such as a match or cigarette lighter.
9. Spiritual awareness; illumination.
a. Something that provides information or clarification: threw some light on the question.
b. A state of awareness or understanding, especially as derived from a particular source: in the light of experience.