A person who marks or labels something, especially with graffiti. The city has been trying to catch the tagger responsible for the graffiti on the bridge.
A person who plays the game of tag, especially the one who chases others. In the game of tag, the tagger must touch another player to pass on the role.
A device or software program that automatically adds tags, labels, or annotations to items or data. The metadata tagger assigned relevant keywords to each document in the archive.