Definitions for "Alga"
A kind of seaweed; pl. the class of cellular cryptogamic plants which includes the black, red, and green seaweeds, as kelp, dulse, sea lettuce, also marine and fresh water confervæ, etc. The algae are primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves.
a plant or plantlike organism; very small green and red algae grow on the skin of manatees; when manatees rub against objects or other manatees, scar like patterns appear where the algae are removed.
single celled green plants usually growing in water; often in long chain, visible to naked eye.
Encyclopaedia Britannica 2002
an organic material and feeds only on inorganic material
a very complex organism
Australian Local Government Association