A device, usually a U-shaped metal hoop on a swivel in the gunwale, used to hold an oar in place and as a fulcrum in rowing.是什么意思_A device, usually a U-shaped metal hoop on a swivel in the gunwale, used to hold an oar in place and as a fulcrum in rowing.在线翻译_英语_读音_用法_例句