The compound adjective 'well-lit' is a transparent combination of two Germanic elements. The adverb 'well,' with its ancient root meaning "wish, desire" in Proto-Indo-European, evolved to signify a positive state or manner. The participial form 'lit' derives from the verb 'light,' whose ultimate origin is the Proto-Indo-European root leuk-, meaning "light, brightness." The logic of the compound is straightforward and literal: a space that is "lit well" or illuminated in a good, sufficient manner. This direct descriptive construction is typical of English compounding, where an adverb modifies a verbal participle to create a clear adjectival meaning, bypassing the need for a Latinate suffix like '-ated' (as in 'illuminated').

Structure: well (in a good manner) + lit (past participle of light) - well: From Old English wel, meaning "in a good manner, satisfactorily." It functions as an adverb modifying the participle. - lit: The past participle of the verb light, from Old English līhtan, līehtan, meaning "to illuminate, to give light." It functions as the core descriptive element.