Definition of "virtual" in English

adjective

1. In effect or essence, rather than in fact or reality; also, imitated, simulated.

   • In fact a defeat on the battlefield, Tet was a virtual victory for the North, owing to its effect on public opinion.
   • Virtual addressing allows computer applications to believe that there is much more physical memory than actually exists.

2. For practical purposes, though not technically; almost complete, very near.

   • The angry peasants were a virtual army as they attacked the castle.

3. Operating using a computer and/or online rather than physically present.

   • a virtual assistant    a virtual personal trainer

4. Simulated in a computer and/or online.

   • virtual machine    virtual memory    virtual private network
   • The virtual world of his computer game allowed character interaction.

5. Of a class member: capable of being overridden with a different implementation in a subclass.

6. (mechanics) Pertaining to a theoretical infinitesimal velocity in a mechanical system that does not violate the system's constraints; also, of other physical quantities: resulting from such a velocity.

   • virtual displacement    virtual work

7. Pertaining to a theoretical quality of something which would produce an observable effect if counteracting factors such as friction are disregarded; specifically, of a head of water: producing a certain pressure if friction, etc., is disregarded.

8. Chiefly in virtual focus: of a focus or point: from which light or other radiation apparently emanates; also, of an image: produced by light that appears to diverge from a point beyond the reflecting or refracting surface.

9. Pertaining to particles in temporary existence due to the Heisenberg uncertainty principle.

10. Of a quantum state: having an intermediate, short-lived, and unobservable nature.

11. Having efficacy or power due to some natural qualities.

12. Having the power of acting without the agency of some material or measurable thing; possessing invisible efficacy.

13. Producing, or able to produce, some result; effective, efficacious.

14. Synonym of virtuous (“full of virtue; having excellent moral character”).

noun

1. (uncountable) Preceded by the: that which is imitated or simulated rather than existing in fact or reality; (countable) an instance of this.

2. (countable, programming) A virtual (adjective adjective, sense 3.3) member function of a class.