Luminances refer to the amount of light or brightness of a given object or place. The antonyms are words that carry the opposite meaning of luminances. Some of the antonyms for luminances include darkness, dullness, gloom, murkiness, obscurity, and shadowiness. Darkness refers to the absence of light, while dullness connotes a lack of brightness, intensity, or liveliness. Gloom implies a state of darkness or dimness, whereas murkiness denotes cloudiness, haziness, or indistinctness. Obscurity carries the connotation of an unrecognizable or unknown entity, and shadowiness refers to darkness cast by shadows. In conclusion, antonyms for luminances describe the opposite of bright light or illumination, and the context determines the appropriate word to use.