What is "alethic"

a. (context logic English) Of or pertaining to the various modality of truth, such as the possibility or impossibility of something being true.

The adjective alethic refers to the various modalities of truth, such as necessity, possibility or impossibility, as in:

• Alethic modality, a modality in linguistics
• Subjunctive or alethic possibility, a form of modality studied in modal logic