Intricate, involved, entangled, complicated, complex.
A genealogical coefficient of a given genealogical tree; defined as the difference between the number of theoretical ancestors of a person and the number of his/her real ones in a given generation (the degree of pedigree collapse).
Complicated, especially of complex technology.
Of a person: having obtained worldly experience, and lacking naiveté; cosmopolitan, worldly-wise.
Of art or other things: appealing to the tastes of an intellectual or sophisticated (sense 1) person; cerebral; also, cultured, elegant, refined.