Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.
Related to diatom: diatomaceous earth
Any of various microscopic one-celled or colonial heterokonts of the class Bacillariophyceae that are photosynthetic, have a silica cell wall made up of two interlocking parts, and form an important component of phytoplankton.
(Microbiology) any microscopic unicellular alga of the phylum Bacillariophyta, occurring in marine or fresh water singly or in colonies, each cell having a cell wall made of two halves and impregnated with silica. See also diatomite
[C19: from New Latin Diatoma (genus name), from Greek diatomos cut in two, from diatemnein to cut through, from dia- + temnein to cut]
di•a•tom(ˈdaɪ ə təm, -ˌtɒm)
any of numerous mostly marine algae of the class Bacillariophyceae (phylum Chrysophyta), each one-celled alga being enclosed in an intricately patterned double shell of silica, one shell fitting over the other like a box lid.
Any of various microscopic one-celled algae that live in water, have hard shells composed mostly of silica, and often live in colonies. Diatom shells are made of two symmetrical parts called valves.
diatomaceous (dī′ə-tə-mā′shəs) adjective
Switch to new thesaurus
|Noun||1.||diatom - microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica|
phytoplankton - photosynthetic or plant constituent of plankton; mainly unicellular algae
alga, algae - primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves