noun. any alga of the genus Chlorella.
1. Noun, singular or mass Not only will this protect the water in which the chlorella is growing, it will also allow the farmer to extend the growing season by helping to keep the water warm for longer periods of time. 2. Noun, plural The National Institutes of Health warns that if you consume chlorella or spirulina harvested from a polluted source, you may consume toxic heavy metals.