Let (M,ω) be a Kähler manifold. An integrable function φ on M is called ω-plurisubharmonic if the current ddφ ∧ ω is positive. We prove that φ is ωplurisubharmonic if and only if φ is subharmonic on all q-dimensional complex subvarieties. We prove that a ωplurisubharmonic function is q-convex, and admits a local approximation by smooth, ω-plurisubharmonic functions. For any closed subvariety Z ...