繼承自中古英語 thriti，繼承自古英語 þrītiġ。
dhirtee
- 三十
- Jacob Poole (1867年)，William Barnes, 编， A glossary, with some pieces of verse, of the old dialect of the English colony in the baronies of Forth and Bargy, County of Wexford, Ireland，J. Russell Smith，ISBN 978-1436729291
