1.  crossover(n = noun.process) crossing over - the interchange of sections between pairing homologous chromosomes during the prophase of meiosis;
is a kind of biological process, organic process
is a part of diplotene

2.  crossover(n = noun.person) crossover voter - a voter who is registered as a member of one political party but who votes in the primary of another party;
is a kind of elector, voter

3.  crossover(n = noun.communication) - 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"
is a kind of adoption, borrowing

4.  crossover(n = noun.artifact) crossing, crosswalk - a path (often marked) where something (as a street or railroad) can be crossed to get from one side to the other;
is a kind of path
has particulars: grade separation, pedestrian crossing, zebra crossing

1.  the interchange of sections between pairing homologous chromosomes during the prophase of meiosis. [WordNet 1.5]

2.  a structure, such as a bridge, bearing a path for crossing over a river or highway. [PJC]

3.  votes from members of one political party cast for candidates of another party; -- called also crossover vote; as, there was a high crossover in this election. [PJC]

4.  a member of one political party who votes for a candidate of another party; -- called also crossover voter. [PJC]

5.  a U-shaped section of pipe which serves to pass one pipeline over another which is directly in its path. [PJC]

crossover, n. & adj.
--n. a point or place of crossing from one side to the other.
--adj. having a crossover.

crossover voter