VIRTUAL
virtual
(adjective) existing in essence or effect though not in actual fact; “a virtual dependence on charity”; “a virtual revolution”; “virtual reality”
Source: WordNet® 3.1
Etymology
Adjective
virtual (not comparable)
In effect or essence, if not in fact or reality; imitated, simulated.
Having the power of acting or of invisible efficacy without the agency of the material or measurable part; potential.
Nearly, almost. (A relatively recent development in meaning)
Simulated in a computer or online.
Operating by computer or in cyberspace; not physically present.
(computing, object-oriented programming, of a class member) Capable of being overridden with a different implementation in a subclass.
(physics) Pertaining to particles in temporary existence due to the Heisenberg uncertainty principle.
Synonyms
• (in effect or essence): de facto
Antonyms
• real
Noun
virtual (plural virtuals)
(computing, programming) A virtual member function of a class.
Source: Wiktionary
Vir"tu*al, a. Etym: [Cf. F. virtuel. See Virtue.]
1. Having the power of acting or of invisible efficacy without the
agency of the material or sensible part; potential; energizing.
Heat and cold have a virtual transition, without communication of
substance. Bacon.
Every kind that lives, Fomented by his virtual power, and warmed.
Milton.
2. Being in essence or effect, not in fact; as, the virtual presence
of a man in his agent or substitute.
A thing has a virtual existence when it has all the conditions
necessary to its actual existence. Fleming.
To mask by slight differences in the manners a virtual identity in
the substance. De Quincey.
Principle of virtual velocities (Mech.), the law that when several
forces are in equilibrium, the algebraic sum of their virtual moments
is equal to zero.
– Virtual focus (Opt.), the point from which rays, having been
rendered divergent by reflection of refraction, appear to issue; the
point at which converging rays would meet if not reflected or
refracted before they reach it.
– Virtual image. (Optics) See under Image.
– Virtual moment (of a force) (Mech.), the product of the intensity
of the force multiplied by the virtual velocity of its point of
application; -- sometimes called virtual work.
– Virtual velocity (Mech.), a minute hypothetical displacement,
assumed in analysis to facilitate the investigation of statical
problems. With respect to any given force of a number of forces
holding a material system in equilibrium, it is the projection, upon
the direction of the force, of a line joining its point of
application with a new position of that point indefinitely near to
the first, to which the point is conceived to have been moved,
without disturbing the equilibrium of the system, or the connections
of its parts with each other. Strictly speaking, it is not a velocity
but a length.
– Virtual work. (Mech.) See Virtual moment, above.
Source: Webster’s Unabridged Dictionary 1913 Edition