ID
ID (ī`dē") , noun
[shortened form of identification.]
any document testifying to the identity of the bearer, especially a card or badge. [capitalized]
Also: I.D.
Id , noun
(Zoology) A small fresh-water cyprinoid fish (Leuciscus idus or Idus idus) of Europe. A domesticated variety, colored like the goldfish, is called orfe in Germany.
id (id) , noun
(Psychoanalysis) That part of a person's psyche which is the unconscious source of impulses seeking gratification or pleasure; the impulses are usually modified by the ego and superego before being acted upon.