sis·co·wet 
(sĭskə-wĕt′)
(sĭskə-wĕt′)n.
A lake trout (Salvelinus namaycush subsp. siscowet) that has a large amount of body fat and is found only in Lake Superior.
[Short for Ojibwa pēmitēwiskawēt : pimitēw-, oil + iskawē, to have flesh of a specified type.]