whaleback Syllabification: (whale·back)Pronunciation: /ˈ(h)wālˌbak/Definition of whaleback noun a thing that is shaped like a whale’s back, especially an arched structure over the bow or stern part of the deck of a steamer, or a large elongated hill: [as modifier]:a whaleback ridgewhaleback in other Oxford dictionaries Definition of whaleback in the British & World English dictionary