ID /(ī`dē")/

ID

n.
  1. any document testifying to the identity of the bearer, especially a card or badge. [capitalized]

Syn. -- ID.

I'd

  1. A contraction from I would or I had; as, I'd go if I could.

Id

n.
  1. 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. (Zool.)

id

n.
  1. 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. (Psychoanalysis)