sta·ble·mate 
/ˈsteɪbəlˌmeɪt/ noun
plural sta·ble·mates /ˈsteɪbəlˌmeɪt/ noun [count] : a horse, person, product, etc., that belongs to the same stable as another horse, person, product, etc.
▪ horses that are stablemates ▪ a new car model and its stablemates
▪ horses that are stablemates ▪ a new car model and its stablemates
