"Illlighted" is a term used to describe a place or area that is poorly lit, dark or dimly lit. The antonym of "illlighted" is "well-lit," which refers to a place that is well-illuminated, bright, and adequately lit. A well-lit environment is essential for creating a safe and inviting space, as it promotes visual clarity and improves the overall mood and atmosphere. Other suitable antonyms for "illlighted" may include "bright," "radiant," "gleaming," "luminous," "shimmering," and "brilliant." These words are associated with light, clarity, and brightness, and when used to describe any environment, they connote a positive ambiance and a welcoming setting.