Synonyms for Saddle (same or very similar meaning)
WordNet sense 1 (a pass or ridge that slopes gently between two peaks (is shaped like a saddle)):
saddlebackWordNet sense 2 (a seat for the rider of a bicycle):
bicycle seatWordNet sense 3 (impose a task upon, assign a responsibility to):
burden, chargeFrom the ODE community, based on WordNetadd/edit