sideboardPronunciation: /ˈsʌɪdbɔːd/Translate sideboard | into French | into German | into Italian | into Spanish Definition of sideboard noun 1a flat-topped piece of furniture with cupboards and drawers, used for storing crockery, glasses, and table linen. 2 (usually sideboards) British a sideburn: bushy sideboards and a moustache 3a board forming the side, or a part of the side, of a structure, especially a removable board at the side of a cart or lorry. sideboard in other Oxford dictionaries Definition of sideboard in the US English dictionary