amoeba
UK[əˈmiːbə]US[əˈmiːbə]
n
a type of very small, single-celled organism that lives in water or as a parasite, can change shape, and reproduces by dividing itself.
Etymology
the word 'amoeba' entered english in the mid-19th century from modern latin, which itself borrowed it directly from the ancient greek word 'amoibē', meaning 'change' or 'alternation'. this greek term is derived from the verb 'ameibein', 'to change'. the name was chosen scientifically to describe the organism's most distinctive characteristic: its constantly changing shape as it moves and feeds by extending parts of its body, called pseudopods. thus, the modern abstract meaning of a shape-shifting microorganism flows directly from the ancient greek concept of change and exchange.
Analysis
this word is a modern latin loanword adopted directly from greek. it is not productively segmented using modern english spelling morphemes.
Examples
under the microscope, we observed an amoeba engulfing a smaller particle.
the amoeba is often studied in introductory biology classes as an example of a simple eukaryote.
infections caused by the amoeba naegleria fowleri are extremely rare but very serious.