The word plus has several meanings:

1. An addition sign in math, written as +. When you see 7 plus 3, you add those numbers together to get 10. The plus sign tells you to combine amounts. Teachers often mark correct answers with a plus sign, turning it into a symbol of approval.
2. Something extra or beneficial that comes with something else. If a hotel room has a great view, that's a plus. When you're deciding between two options and one has more advantages, those advantages are called pluses. You might say “The job pays well, plus I'd get to work with my friends.”
3. In casual speech, plus often replaces “and” when listing reasons: “I don't want to go to the pool. It's too cold, plus I have homework.”
4. When describing amounts, plus means “or more.” If a sign says “Ages 12 plus,” it means 12 years old and older. A temperature of 80 degrees plus means at least 80, possibly higher.

The word suggests addition whether you're adding numbers, adding benefits to a decision, or adding to a minimum amount. It points toward more.