Learner's definition of IDENTIFICATION
1 : the act of finding out who someone is or what something is : the act of identifying someone or something
2 [noncount] : something that shows who a person is : a document, card, etc., that has your name and other information about you and that often includes your photograph
We were told to carry (some) personal identification at all times.
He needed to show (his) identification before they would cash the check.
You need two forms of identification.
3 [noncount] : a feeling that you share and understand the problems or experiences of another person : the act of identifying with someone