Pro is short for professional, meaning someone who gets paid to do something because they're highly skilled at it. A pro basketball player earns a living playing basketball, unlike someone who just plays for fun in their driveway. When you call someone a pro, you're saying they're really good at what they do, whether it's a pro chef, a pro musician, or a pro video game player.

The word also means the advantages or positive aspects of something. When making a decision, you might list the pros and cons: the pros are reasons to do something, while the cons are reasons not to. If you're deciding whether to join the soccer team, the pros might include making new friends and getting exercise, while the cons might include less free time and early Saturday practices.

Pro can also be a prefix meaning “in favor of” or “supporting.” Someone who is pro-education strongly supports schools and learning. A pro-democracy movement works to establish or protect democratic government. In this usage, pro always appears attached to another word with a hyphen to show which side of an issue someone supports.