The antonyms for the word 'loses brightness' can be 'gains luster', 'shimmers', 'sparkles' or 'glows'. Losing brightness means to become dull or faded, but gaining luster means to become brighter and more sparkling. Shimmering implies a gentle wavering light, while sparkling suggests a bright, twinkling light. On the other hand, glowing gives an impression of warm radiance, making an object or person appear brighter and more attractive. The antonyms of losing brightness are important, as they describe the opposite effect, and can be used to convey a sense of brightness, energy, and life. By choosing the right antonym, you can enhance the meaning of your sentences and make them more impactful.