Meaning

• A small label.

• A children's chasing game in which one player (known as "it") attempts to touch another, who then becomes "it".

• A skin tag, an excrescence of skin.

• A type of cardboard.

• Graffiti in the form of a stylized signature particular to the artist.

• A dangling lock of sheep's wool, matted with dung; a dung tag.

• (authorship) An attribution in narrated dialogue (eg, "he said") or attributed words (e.g. "he thought").

• The last line (or last two lines) of a song's chorus that is repeated to indicate the end of the song.

• The last scene of a TV program that often focuses on the program's subplot.

• A vehicle number plate; a medal bearing identification data (animals, soldiers).

  "The subwoofer in the trunk was so loud, it vibrated the tag like an aluminum can."

• An instance of touching the baserunner with the ball or the ball in a gloved hand to rule him "out."

  "The tag was applied at second for the final out."

• A piece of markup representing an element in a markup language.

  "The tag conveys sarcasm in Internet slang."

• A keyword, term, or phrase associated with or assigned to data, media, and/or information enabling keyword-based classification; often used to categorize content.

  "I want to add genre and artist tags to the files in my music collection."

• Any slight appendage, as to an article of dress; something slight hanging loosely.

• A metallic binding, tube, or point, at the end of a string, or lace, to stiffen it.

• The end, or catchword, of an actor's speech; cue.

• Something mean and paltry; the rabble.

• A sheep in its first year.

• Any short peptide sequence artificially attached to proteins mostly in order to help purify, solubilize or visualize these proteins.

• A person's name.

  "What's your tag?"

Meaning

• To label (something).

• (graffiti) To mark (something) with one’s tag.

• To remove dung tags from a sheep.

  "Regularly tag the rear ends of your sheep."

• To hit the ball hard.

  "He really tagged that ball."

• To put a runner out by touching them with the ball or the ball in a gloved hand.

  "He tagged the runner for the out."

• To mark with a tag (metadata for classification).

  "I am tagging my music files by artist and genre."

• To follow closely, accompany, tag along.

• To catch and touch (a player in the game of tag).

• To fit with, or as if with, a tag or tags.

• To fasten; to attach.