Where a boy/man moves onto the 'bases' on relationships frequently or too quickly. eg first base (kiss) second base (oral) so on.

Preferably moving quite frequently, onto many girls, doing sexual activities. Known also as a player.
Harry: I got sucked off by Kirsten yesterday night, but the day before fingered Katy in a bush!

Martin: Harry you baseman!

Or

Cindy: Did you hear that Harry got head off Kirsten but fingered Katy and tried to have sex with Marie!

Laura: Ew, OMG, what a baseman
by Hahayoubaseman November 3, 2013
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A guy who doesn’t have sex, opting to draw the line at fellatio, cunnilingus, and other heavy petting, all while avoiding ejactulation; Voluntarily celibate - volcel
Girl: “Mmm your couch is so comfy and you smell really good”
Guy: “You’re such a sweet gell
*sometime later*
Girl: “Omg! Put it in me!!”
Guy: “Hahaha! I’m a third baseman! I’ll be keeping my cum!”
by Smykovsy January 22, 2021
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A second baseman is a person is either baseball or softball that plays second base. They typically do not get much hit to them but when they do they are on their toes. Their specialties include covering first and second as well as covering the base in a run down which they always enjoy. Typically the most enthusiastic on the team and hyper about getting to play their position. Second basemen always rock a face mask when chosen. Most second basemens take possession over the base second and are very protective over their spot.
Person 1: “dude did you see how hyper she was covering second for that run down!!”

Person 2: “yep! She must be the second baseman.”
by allielovesunicorns January 4, 2019
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A knowledgeable person you bring with you when negotiating a deal for a new car.
I brought Chris with me as my third baseman when I bought my new Audi. He ended up saving me thousands of dollars.
by tiab guls May 22, 2014
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As a man, your third baseman is the only other man that you would a have a threesome with thus making it you, the girl and of course your third baseman. Most of the time this person would be you best friend, your bro, or someone you are close to and have known for a while. Your third baseman is someone who wouldn't judge and someone who you know that won't make it weird or awkward afterwards.
Girl: the only way I'm having a threesome is if its with two guys,
Guy: alright Im in
Girl: better get your third baseman
by theTrooper January 10, 2013
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