predominantly photosynthetic prokaryotic organisms containing a blue pigment as well as chlorophyll; occur singly or perhaps in colonies in diverse habitats; crucial as phytoplankton
A figure of speech in which the expression is an evident exaggeration of the meaning intended to be conveyed or by which things are represented as much greater or less better or worse than they really are a statement exaggerated fancifully through excitement or for effect...
How would you define blue-green algae?