What does "relieving" mean?

Relieving: Serving or tending to relieve. Relieving arch (Arch.), a discharging arch. See under Discharge, v. t. -- Relieving tackle. (Naut.) (a) A temporary tackle attached to the tiller of a vessel during gales or an action, in case of accident to the tiller ropes. (b) A strong tackle from a wharf to a careened vessel, to prevent her from going over entirely, and to assist in righting her. Totten. Craig.