diatom
noun
di·a·tom ˈdī-ə-ˌtäm 
: any of a class (Bacillariophyceae) of minute planktonic unicellular or colonial algae with silicified skeletons that form diatomaceous earth
Example Sentences
Recent Examples on the Web Under this scenario, a spider in the Cenozoic era would expire and become entrapped in a diatom mat. 
Jennifer Ouellette, Ars Technica, 26 Apr. 2022 Prior studies suggested the diatom mats would have created an anaerobic environment, thanks to extracellular polymeric substances. Jennifer Ouellette, Ars Technica, 26 Apr. 2022 The algal cell pictured here in red, a Coscinodiscus diatom, is 90 micrometers across, or one tenth the width of a ballpoint pen’s tip. Leslie Nemo, Scientific American, 19 Feb. 2021 Because small fish in the lakes eat zooplankton, a plunge in the diatom numbers would cause fish populations to crash. Tim Folger, National Geographic, 17 Nov. 2020 Going a step further, Martin proposed that using iron to trigger diatom blooms might help combat global warming. Emily Underwood, Smithsonian Magazine, 3 Jan. 2020 When a krill dies, the powerful enzymes in its belly that dissolve diatoms turn on and swiftly autodigest the body. Lucy Jakub, Harper's magazine, 2 Mar. 2020 To reconstruct lake levels as far back as 18,000 years, scientists examined diatoms (a type of algae) collected from the bottom of the lake to see how fresh or brackish the water used to be. Emily J. Beverly, Quartz Africa, 26 Jan. 2020 Brackish diatoms indicate lower lake levels because the water becomes saltier as the water evaporates. Emily J. Beverly, Quartz Africa, 26 Jan. 2020 See More
Jennifer Ouellette, Ars Technica, 26 Apr. 2022 Prior studies suggested the diatom mats would have created an anaerobic environment, thanks to extracellular polymeric substances. Jennifer Ouellette, Ars Technica, 26 Apr. 2022 The algal cell pictured here in red, a Coscinodiscus diatom, is 90 micrometers across, or one tenth the width of a ballpoint pen’s tip. Leslie Nemo, Scientific American, 19 Feb. 2021 Because small fish in the lakes eat zooplankton, a plunge in the diatom numbers would cause fish populations to crash. Tim Folger, National Geographic, 17 Nov. 2020 Going a step further, Martin proposed that using iron to trigger diatom blooms might help combat global warming. Emily Underwood, Smithsonian Magazine, 3 Jan. 2020 When a krill dies, the powerful enzymes in its belly that dissolve diatoms turn on and swiftly autodigest the body. Lucy Jakub, Harper's magazine, 2 Mar. 2020 To reconstruct lake levels as far back as 18,000 years, scientists examined diatoms (a type of algae) collected from the bottom of the lake to see how fresh or brackish the water used to be. Emily J. Beverly, Quartz Africa, 26 Jan. 2020 Brackish diatoms indicate lower lake levels because the water becomes saltier as the water evaporates. Emily J. Beverly, Quartz Africa, 26 Jan. 2020 See More Word History
Etymology
ultimately from Greek diatomos cut in half, from diatemnein to cut through, from dia- + temnein to cut — more at tome
First Known Use
1845, in the meaning defined above
Medical Definition
diatom
noun
di·a·tom ˈdī-ə-ˌtäm
: any of a class (Bacillariophyceae) of minute planktonic unicellular or colonial algae with silicified skeletons that form diatomite
- back in action
- back in business
- back in circulation
- back in/into circulation
- back into
- back into circulation
- back is against the wall
- back is to the wall
- back is to/against the wall
- back issues
- back judge
- back line
- back lines
- back load
- back loop jump
- back lot
- back lots
- back marker
- back matter
- back mutation
- back nine
- back number
- back of
- back of beyond
- back of one's hand