noun

• (music) An electronic music track without an official title.
• (radio, television) An ident.
  "If not done at the top of the hour, however, the station ID should come at the next possible break in the programme."
• (Internet) Initialism of image description.
• (nutrition) Initialism of iron deficiency.

verb

• (transitive) To identify (an object, etc.).
  "Police have been unable to ID the body found in the river."
• (transitive) To request to see a person’s identification for proof of identity or age.
  "The bartender will have to ID you before serving you a drink."
• (intransitive) To identify (as something)
  "I have one black grandfather, but I don't ID as mixed race"

noun

• (psychoanalysis) The unconscious impulsive component of the personality in the Freudian psychoanalytic model.
  ""There is one sentence in it, however - namely: 'I protest strongly against the insufferable and entirely dogmatic assertion that each separate id is a microcosm possessed of an historical architecture elaborated slowly through the series of generations.' Have you no desire, in view of later research, to modify this statement?""

noun

• (computing) Identifier.