An order of fishes having barbels in the jaws. It includes the catfishes, or siluroids. See siluroid.
others:
An order of teleost fishes where the supramaxillary bones are horizontal and brief or rudimentary, and covered with epidermis which types barbels at each and every part for the mouth, whence the name; the nematognaths or catfishes.
How would you define nematognathi?