Illustration of amoeba
- 1 pseudopodium
- 2 nucleus
- 3 contractile vacuole
- 4 food vacuole
amoeba
noun
amoe·ba ə-ˈmē-bə 
variants or less commonly ameba
plural amoebas or amoebae also amebas or amebae ə-ˈmē-(ˌ)bē
: any of a large genus (Amoeba) of naked rhizopod protozoans with lobed and never anastomosing pseudopodia, without permanent organelles or supporting structures, and of wide distribution in fresh and salt water and moist terrestrial environments
broadly : a naked rhizopod or other amoeboid protozoan
amoebic adjective
or less commonly amebic
ə-ˈmē-bik
Example Sentences
Recent Examples on the Web This summer, two people sadly died after being infected by Naegleria fowleri, an organism that is commonly referred to as a brain-eating amoeba. 
Maggie O'neill, SELF, 30 Aug. 2022 And a child in North Texas died in September after contracting the brain-eating amoeba at a public splash pad. Rebekah Riess, Holly Yan And Amanda Sealy, CNN, 19 Aug. 2022 Brain-eating amoeba are rare in the U.S., according to the CDC. Max Thornberry, Fox News, 18 Aug. 2022 Naegleria fowleri is an amoeba commonly found in warm freshwater lakes, rivers, canals and ponds throughout the United States, the Nebraska health department said. Rebekah Riess, Holly Yan And Amanda Sealy, CNN, 19 Aug. 2022 The amoeba isn’t found in salt water, according to the CDC. Ashley R. Williams, USA TODAY, 16 July 2022 Symptoms of brain-eating amoeba generally start one to nine days after nasal exposure and many people die within 18 days of showing symptoms, according to the CDC. Vanessa Etienne, PEOPLE.com, 11 July 2022 Health officials believe the child came into contact with the amoeba on Sunday while swimming in the Elkhorn River just west of Omaha. Margery A. Beck And Josh Funk, Anchorage Daily News, 18 Aug. 2022 Last month, a Missouri resident died in southwestern Iowa of the same infection probably caused by the amoeba. Washington Post, 18 Aug. 2022 See More
Maggie O'neill, SELF, 30 Aug. 2022 And a child in North Texas died in September after contracting the brain-eating amoeba at a public splash pad. Rebekah Riess, Holly Yan And Amanda Sealy, CNN, 19 Aug. 2022 Brain-eating amoeba are rare in the U.S., according to the CDC. Max Thornberry, Fox News, 18 Aug. 2022 Naegleria fowleri is an amoeba commonly found in warm freshwater lakes, rivers, canals and ponds throughout the United States, the Nebraska health department said. Rebekah Riess, Holly Yan And Amanda Sealy, CNN, 19 Aug. 2022 The amoeba isn’t found in salt water, according to the CDC. Ashley R. Williams, USA TODAY, 16 July 2022 Symptoms of brain-eating amoeba generally start one to nine days after nasal exposure and many people die within 18 days of showing symptoms, according to the CDC. Vanessa Etienne, PEOPLE.com, 11 July 2022 Health officials believe the child came into contact with the amoeba on Sunday while swimming in the Elkhorn River just west of Omaha. Margery A. Beck And Josh Funk, Anchorage Daily News, 18 Aug. 2022 Last month, a Missouri resident died in southwestern Iowa of the same infection probably caused by the amoeba. Washington Post, 18 Aug. 2022 See More Word History
Etymology
New Latin, genus name, from Greek amoibē change, from ameibein to change — more at migrate
First Known Use
1822, in the meaning defined above
Kids Definition
amoeba
noun
amoe·ba ə-ˈmē-bə
plural amoebas or amoebae
-bē
: a tiny water animal that is a single cell which flows about and takes in food
Medical Definition
amoeba
noun
amoe·ba
ə-ˈmē-bə
1
capitalized : a large genus of naked rhizopod protozoans that have lobed and never anastomosing pseudopodia and are widely distributed in fresh and salt water and moist terrestrial environments
2
also ameba plural amoebas or amoebae -(ˌ)bē also amebas or amebae : a protozoan of the genus Amoeba
also amebas or amebae : a protozoan of the genus Amoeba broadly : an amoeboid protozoan (as a naked rhizopod)