x1 reflects/pertains to the Indian Ocean region/culture/history/geography/identity/[nationality] in aspect x2.
Pertains to peoples or things bordering, embedded in (or on an island in), submerged in, located under or on the bottom of, or going through/over the Indian Ocean as well. "Trans-Indian" (in the sense of pertaining to the Indian Ocean) is closely related to this word. See also: ".atlanto", "pakfiko".