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.
Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 5 Various
the former name for cyanobacteria
See under cyanobacterium.
blue-hair Historical Examples Milton’s Comus John Milton
a print made on light-sensitive paper and used as a proof for checking the position of stripped-up negatives or positives and copy prior to platemaking.
noun a highly venomous octopus, Octopus maculosus, of E Australia which exhibits blue bands on its tentacles when disturbed
adjective (Austral) working-class