noun

• (uncountable) The quality or state of being a fact.
  "[F]rom the earliest times down to the middle of the last century the writers of the Jewish and Christian Churches, with the exception of the Deists in England and of some isolated views, unanimously held fast the facticity of the events recorded in this book [the Book of Jonah in the Bible]."
• (uncountable, specifically, philosophy) In existentialism, the state of being in the world without any knowable reason for such existence, or of being in a particular state of affairs which one has no control over.
  "For as sure as the absolute knowledge (in the infinite facticity—actual existence—of each single knowledge) is only in the absolute form of the For-itself, so sure each knowledge goes also beyond itself; or, viewed from another point, is in its own Being absolutely outside of itself, and encircles itself entire."
• (countable) A fact that is not changeable or that is assumed to be true without further evaluation.
  "Near-synonyms: given, axiom, postulate"