word-forming element meaning "quality, condition; act, power, skill; office, position; relation between," Middle English -schipe, from Old English -sciepe, Anglian -scip "state, condition of being," from Proto-Germanic *-skepi- (cognates: Old Norse -skapr, Danish -skab, Old Frisian -skip, Dutch -schap, German -schaft), from *skap- "to create, ordain, appoint," from PIE root *(s)kep-, forming words meaning "to cut, scrape, hack" (see shape (v.)). It often forms abstracts to go with corresponding concretes (friend/friendship, etc.).
<a href="https://www.etymonline.com/word/bipartisanship">Etymology of bipartisanship by etymonline</a>
Harper, D. (n.d.). Etymology of bipartisanship. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/bipartisanship