trucial (adj.)youdaoicibaDictYouDict[trucial 词源字典]
1876, from truce + -ial. Trucial States, the pre-1971 name of the United Arab Emirates, is attested from 1891, in reference to the 1835 maritime truce between Britain and the Arab sheiks of Oman.[trucial etymology, trucial origin, 英语词源]