The word 'unlighted' is a straightforward English formation built from native Germanic elements. Its core, 'light,' descends from the Proto-Germanic leuhtą, itself from the Proto-Indo-European root leuk-, meaning "light, brightness." The prefix 'un-,' one of the oldest and most common negators in English, attaches to create the opposite sense. The suffix '-ed' is added to the noun 'light,' following a pattern seen in words like 'talented' or 'walled,' to form an adjective meaning "characterized by (a lack of) light." Thus, the word's logic is transparent: it literally describes a state of "not having been provided with brightness."

Structure: un (not) + light (brightness) + ed (adjective suffix) - un: A prefix of Germanic origin (Old English un-), meaning "not." It functions as a negative particle. - light: A root of Germanic origin (Old English lēoht), meaning "brightness" or "illumination." It functions as the core noun denoting the source or condition. - ed: A suffix of Germanic origin (Old English -ed, -od), originally forming past participles of verbs, here used to create an adjective meaning "having the quality of."