Siluroid \Si*lu"roid\, n. [Silurus + -oid.] (Zo["o]l.) Belonging to the Siluroidei, or Nematognathi, an order of fishes including numerous species, among which are the American catfishes and numerous allied fresh-water species of the Old World, as the sheatfish ({Silurus glanis}) of Europe. -- n. A siluroid fish.