- lightless - giving no light; "lightless stars `visible' only to radio antennae"
Antonyms: visible, seeable (indirect, via invisible)
- lightless, unilluminated, unlighted, unlit - without illumination; "came up the lightless stairs"; "the unilluminated side of Mars"; "through dark unlighted (or unlit) streets"
Antonym: light (indirect, via dark)