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.
Entries linking to trucial
truce n.
"mutually agreed-upon temporary intermission of hostilities," early 13c., triws, variant of trewes, originally plural of trewe "faith, assurance of faith, covenant, treaty," from Old English treow "faith, truth, fidelity; pledge, promise, agreement, treaty," from Proto-Germanic *treuwo- (source also of Old Frisian triuwe, Middle Dutch trouwe, Dutch trouw, Old High German triuwa, German treue, Gothic triggwa "faith, faithfulness"), from PIE root *deru- "be firm, solid, steadfast." Related to true (adj.). The Germanic word was borrowed into Late Latin as tregua, hence French trève, Italian tregua.
-ial
adjectival word-forming element, variant of -al (1) with connective -i-. From Latin -ialis, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective.