virtual

adjective

• 1almost or nearly as described, but not completely or according to strict definition:the virtual absence of border controls

• 2 Computing not physically existing as such but made by software to appear to do so:virtual imagesSee also virtual reality.
• carried out, accessed, or stored by means of a computer, especially over a network:a virtual library virtual learning

• 3 Optics relating to the points at which rays would meet if produced backwards.

• 4 Mechanics relating to or denoting infinitesimal displacements of a point in a system.

• 5 Physics denoting particles or interactions with extremely short lifetimes and (owing to the uncertainty principle) indefinitely great energies, postulated as intermediates in some processes.