The Collaborative International Dictionary
Suburbicarian
Suburbicarian \Sub*ur`bi*ca"ri*an\, Suburbicary \Sub*ur"bi*ca*ry\, a. [LL. suburbicarius, equiv. to L. suburbanus: cf. F. suburbicaire. See Suburban.] Being in the suburbs; -- applied to the six dioceses in the suburbs of Rome subject to the pope as bishop of Rome.
The pope having stretched his authority beyond the
bounds of his suburbicarian precincts.
--Barrow.
Wiktionary
suburbicarian
a. (''In the Roman Catholic church'') Describing any of the six dioceses surrounding Rome. These dioceses are always headed by cardinal of the high#Adjective rank.