As I mentioned when they consulted for the feminine, it is a linguistic spawn by quinquepartite, which is taken from Latin. Abusing a little of the flexibility of the language one can invent some totally Greek meanings for 10060;pentapartite, such as "form a row of five" or "align with pain or with lament" (128558; ) . But it is not worth it as an etymological game. See tripartite, quadripartite.
