Definition of thirty :
1. A symbol expressing thirty, as 30, or XXX.
2. Being three times ten; consisting of one more than twenty- nine; twenty and ten; as, the month of June consists of thirty days.
3. The sum of three tens, or twenty and ten; thirty units or objects.
- I shall, as I think I told you, be worth about thirty dollars when the month is out. - "A Damaged Reputation", Harold Bindloss.
- You, too, have lost a son, so you know now how he has felt for thirty- two years. - "The Awakening of Helena Richie", Margaret Deland.
- Thirty men live in the drawing- room. - "The First Hundred Thousand", Ian Hay.