IPA: /ɪnˈvɪzəblnəs/
KK: /ɪnˈvɪzəblnəs/
The condition of not being able to be seen; the quality of being unseen.
The invisibleness of the ghost made it difficult to detect.
Invisibleness → It is formed from "in-" (meaning not) and "visibilis" (from Latin, meaning able to be seen) and the suffix "-ness" (meaning the state of being). The word "invisibleness" refers to the state of not being able to be seen.
Think of 'not' ('in-') being able to be 'seen' ('visibilis') — that's why invisibleness means the state of being not visible.