Real Dictionary

tag
countable noun: A tag is a small piece of card or cloth which is attached to an object or person and has information about that object or person on it.

tag in American English
a hanging end or rag, as on a torn skirt

tag in American English 1
intransitive verb: to follow closely; go along or about as a follower
noun: a piece or strip of strong paper, plastic, metal, leather, etc., for attaching by one end to something as a mark or label
transitive verb: to furnish with a tag or tags; attach a tag to

tag in American English 2
noun: a children's game in which one player chases the others in an effort to touch one of them, who then takes the role of pursuer
transitive verb: to touch in or as if in the game of tag

tag in British English 1
noun: a piece or strip of paper, plastic, leather, etc, for attaching to something by one end as a mark or label

tag in British English 2
noun: a children's game in which one player chases the others in an attempt to catch one of them who will then become the chaser
verb: to catch (another child) in the game of tag

tag in Retail
noun: A tag is a plastic, fabric or cardboard label attached to a product, such as a hang tag or security tag.