trucial
adjective
tru·cial
ˈtrüshəl,
-üsēəl
often capitalized
: of, relating to, or involving several territorial areas in the vicinity of the Persian Gulf for which the government of Great Britain formerly assumed responsibility nominally in an advisory capacity
nearly 400 miles of coast belongs to the Trucial sheikhs 
Americana Annual
Americana Annual
Word History
Etymology
truce entry 1 + -ial; from the maritime truce made in 1835 between the British government and several Arab states of the Oman peninsula