plural noun Biology.
a widely distributed group of predominantly photosynthetic prokaryotic organisms of the subkingdom Cyanophyta, resembling phototrophic bacteria, occurring singly or in colonies in diverse habitats: some species can fix atmospheric nitrogen.
Origin of blue-green algae
First recorded in 1895–1900
Also called cyanobacteria.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for blue-green algae
the former name for cyanobacteria
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