n. The science of the inward and essential nature of things.n. [Used frequently with the definite article, and generally connected with unpleasant associations, as being a study very dry and at the same time of doubtful truth.n. Philosophy in general; especially, the philosophical study of mind; psychology: so used from the time of Descartes, and especially by the Scotch school.n. In the Kantian terminology, the science of God, freedom, and immortality. Abbreviated metaphysics