What does "tag" mean?

Additional senses

1. 2.The end, or catchword, of an actor's speech; cue.
2. 3.Something mean and paltry; the rabble. [Obs.] Tag and rag, the lowest sort; the rabble. Holinshed.
3. 4.A sheep of the first year. [Prov. Eng.] Halliwell. A sale of usually used items (such as furniture, clothing, household items or bric-a-brac), conducted by one or a small group of individuals, at a location which is not a normal retail establishment. Note: Frequently it is held in the private home or in a yard attached to a private home belonging to the seller. Similar to a yard sale or garage sale. Compare flea market, where used items are sold by many individuals in a place rented for the purpose.
4. 5.To fit with, or as with, a tag or tags. He learned to make long-tagged thread laces. Macaulay. His courteous host . . . Tags every sentence with some fawning word. Dryden.
5. 6.To join; to fasten; to attach. Bolingbroke.
6. 7.To follow closely after; esp., to follow and touch in the game of tag. See Tag, a play.
7. 8.To follow closely, as it were an appendage; -- often with after; as, to tag after a person.
8. 9.A child's play in which one runs after and touches another, and then runs away to avoid being touched.