tagger

noun

1. The player who tries to catch others in the game of tag.
2. A person who writes graffiti using a specific mark
3. A program or algorithm that adds tags for purposes of categorization, e.g. grammatical information to words in a document, or genres to songs in a music collection.
4. A device for removing taglocks from sheep.
5. That which is pointed like a tag.
6. The penis.
7. Sheets of tin or other plate which run below the gauge.