- 1number 30
- 2noun the thirties [plural] numbers, years, or temperatures from 30 to 39 Idioms
between the ages of 30 and 39
in your thirtiesjump to other results
thirtiethjump to other results
NAmE//ˈθərt̮iəθ//ordinal number, noun There are examples of how to use ordinal numbers at the entry for fifth.