Blad·der·wort n. Bot. A genus (Utricularia) of aquatic or marshy plants, which usually bear numerous vesicles in the divisions of the leaves. These serve as traps for minute animals. See Ascidium.
n : any of numerous aquatic carnivorous plants of the genus
Utricularia some of whose leaves are modified as small
urn-shaped bladders that trap minute aquatic animals