http://www.thefreedictionary.com/I'd

id (ɪd)

n. Psychoanal.
the part of the psyche that is the source of unconscious and instinctive impulses that seek satisfaction in accordance with the pleasure principle. Compare ego (def. 2), superego.

ID's, IDs
v., ID'd or IDed or ID'ed, ID'ing or ID•ing.
1. a means of identification, as a document containing information regarding the bearer's identity.
v.t.

I.D.
1. identification.
2. identity.
3. Intelligence Department.