un ‧ lit /ˌʌnˈlɪt◂/ BrE AmE adjective
[ Word Family: noun : ↑ light , ↑ lighter , ↑ lighting , ↑ lightness ; adjective : ↑ light , ↑ lighted , ↑ unlit ; verb : ↑ light , ↑ lighten ; adverb : ↑ lightly , ↑ light ]
dark because there are no lights:
an unlit stairway