Existence
Existence was the reality state of being real or alive.
A time-traveling Gabrielle Burnham observed that Spock's dyslexia allowed him to process the effects of atemporal dysplasia. Together with his logic training and Human emotions, this helped him comprehend her existence. (DIS: "Perpetual Infinity")
In 2369, Commander Benjamin Sisko attempted to explain the concepts of linear time and corporeal existence to the Prophets, who were themselves non-corporeal lifeforms whose existence was outside of linear time. They told him that what comes before is no different than what is now or what is to come, that it is one's existence. He told them that members of his species lived in one point in time, that once they moved beyond it, it became the past and that anything in the future did not exist for them, that this was the nature of linear existence. They, however, showed him a scenario with his deceased wife Jennifer Sisko, telling him "She is a part of your existence." He told them that she was a part of it, that she was no longer alive, that he had lost her, that in a linear existence, one could not go back to something that was left behind, so it was lost. They, however, told him that this was his existence, showing him the time of Jennifer Sisko's death. "You exist here," they told him, and through this, he realized that he did in fact exist there, that he never truly accepted her death and therefore had not moved beyond in the manner he claimed to them that he had. "It's not linear," he admitted, and truly began to grieve for his lost wife. (DS9: "Emissary")