Cogitarisexual is an ace-spec microlabel for individuals who only experience attraction within their own head. They may experience sexual attraction when imagining it, when imagining certain things, or when thinking about certain individuals/things, but they only experience that attraction because they're imagining something. They do not experience actual sexual attraction in real life, and have no desire to act on the attraction they experience in their imagination.
Cogitarisexual individuals may have a sexual orientation in their imagination. For example, one may only experience sexual attraction to men and non-binary individuals in their imagination, or they may only be attracted to women in their imagination. If that's the case, one may choose to add "cogitari-" as a prefix to another sexual orientation to specify the attraction they experience. For example, someone who is cogitarisexual and, when they do experience attraction in their head, they experience it to men and non-binary individuals, they may say they're cogitaritorensexual to describe themselves.