Being three times ten; consisting of one more than twenty-nine; twenty and ten; as, the month of June consists of thirty days.
- The cardinal number equal to 3 × 10.
- A decade or the numbers from 30 to 39: They settled down in their thirties. The temperature fell into the thirties.
- The decade from 30 to 39 in a century.
- An indication of the end of a news story, usually written 30.
- Sports The second point that is scored by one side in tennis.