\A*nad"ro*mous\, a. [Gr. ? running upward; ? + ? a running, ? to run.] 1. (Zo["o]l.) Ascending rivers from the sea, at certain seasons, for breeding, as the salmon, shad, etc. 2. (Bot.) Tending upwards; -- said of terns in which the lowest secondary segments are on the upper side of the branch of the central stem. --D. C. Eaton.