• (n.) A small, handsome trout (Salvelinus oquassa), found in some of the lakes in Maine; -- called also blueback trout.
O·quas'sa noun (Zoology) A small, handsome trout ( Salvelinus oquassa ), found in some of the lakes in Maine; -- called also blueback trout . 
a small, dark-blue brook trout, Salvelinus oquassa, of Maine.