a submerged aquatic plant, Hydrilla verticillata, native to the Old World, that has become a pest weed in U.S. lakes and waterways.
Origin of hydrilla
< New Latin (1814), the genus name, equivalent to Latin hydr(a) hydra + -illa diminutive suffix
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any aquatic plant of the Eurasian genus Hydrilla, growing underwater and forming large masses: used as an oxygenator in aquaria and pools. It was introduced in the S US where it has become a serious problem, choking fish and hindering navigation
Word Origin for hydrilla
C20: New Latin, probably from hydra
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012