A phrase used to describe something or someone that is completely absent or invisible. It implies a complete lack of presence or visibility, emphasizing the absence of both physical and visual presence. It can also be used to express the feeling of being unnoticed or overlooked, as if one is not there at all. This phrase can also be used figuratively to describe a situation or concept that is difficult to grasp or understand, as if it is not there or cannot be seen. Overall, ‘not there not seen’ conveys a sense of emptiness, invisibility, and obscurity.