crossover

the interchange of sections between pairing homologous chromosomes during the prophase of meiosis

a voter who is registered as a member of one political party but who votes in the primary of another party

the appropriation of a new style (especially in popular music) by combining elements of different genres in order to appeal to a wider audience; "a jazz-classical crossover album"

a path (often marked) where something (as a street or railroad) can be crossed to get from one side to the other