1) Delitescence 2) French word used in English 3) Imperceptibility 4) Indistinctness 5) Invisibleness 6) Mystery 7) Nonappearance 8) Physical property 1) Inconspicuousness 2) Invisibleness 
Invisibility is the state of an object that cannot be seen. An object in this state is said to be invisible (literally, `not visible`). The term is often used in fantasy/science fiction, where objects are literally made unseeable by magical or technological means; however, its effects can also be demonstrated in the real world, particularly in p.....
• (n.) The state or quality of being invisible; also, that which is invisible.
In·vis`i·bil'i·ty noun ; plural Invisibilities . [ Latin invisibilitas : confer French invisibilité .] The state or quality of being invisible; also, that which is invisible. 'Atoms and invisibilities .' Landor. 
[n] - the quality of not being perceivable by the eye
invisibleness noun the quality of not being perceivable by the eye