A Suppositum
A completion of a substance which ontologically dividuates it as a whole.
E.g., this rock, this tree, this person, etc.
This completion is not the mere abstraction of the total of existence of an entity (e.g., this entire rock I will refer to as a suppositum); but, rather, it is an ontologically distinct completion from the substance which it completes. However, since a part cannot be identical to its whole, the suppositum cannot be a part of the entity which it is the completion of. See “Ontological Divviduation” for a more in-depth analysis of a suppositum.