The Collaborative International Dictionary of English v.0.48:

Cargoose \Car"goose`\, n. [Perh. fr. Gael. & Ir. cir, cior
   (pronounced kir, kior), crest, comb + E. goose. Cf. Crebe.]
   (Zool.)
   A species of grebe (Podiceps crisratus); the crested grebe.
   [1913 Webster]