Source : Webster's Revised Unabridged Dictionary (1913)

Sewellel \Se*wel"lel\, n. [Of American Indian origin.]
   (Zo["o]l.)
   A peculiar gregarious burrowing rodent ({Haplodon rufus}),
   native of the coast region of the Northwestern United States.
   It somewhat resembles a muskrat or marmot, but has only a
   rudimentary tail. Its head is broad, its eyes are small and
   its fur is brownish above, gray beneath. It constitutes the
   family {Haplodontid[ae]}. Called also {boomer}, {showt'l},
   and {mountain beaver}.