*hogback*

n. 1. (Arch.) An upward curve or very obtuse angle in the upper surface of any member, as of a timber laid horizontally; -- the opposite of camber. [ 1913 Webster ]

2. (Naut.) See Hogframe. [ 1913 Webster ]

3. (Geol.) A ridge formed by tilted strata; hence, any ridge with a sharp summit, and steeply sloping sides. [ 1913 Webster ]