Ca*tad"ro*mous (?), a. [Gr. down + a running.]
1. Bot.
Having the lowest inferior segment of a pinna nearer the rachis than the lowest superior one; -- said of a mode of branching in ferns, and opposed to anadromous.
2. Zool.
Living in fresh water, and going to the sea to spawn; -- opposed to anadromous, and of the eel.
© Webster 1913.