One-bagger is a baseball term, referring to a play in which a batter hits a single and safely makes it to first base. To describe this play using a synonym, you could use the term "singles hitter." This term captures the idea that the batter is someone who tends to hit singles. Additionally, you could use the phrase "one-base hit," which more closely describes the action of the play. Finally, you could use the term "base knock" to describe a single hit that makes it to first base. All of these synonyms effectively capture the essence of a one-bagger.