bacterium
n. countablen. a tiny living thing that is so small you can only see it with a microscope. Some of these can make you sick, while others are helpful for your body.
n. a microscopic, single-celled organism that lacks a distinct nucleus and may be found in diverse environments. While many species are pathogenic, others are essential for processes like fermentation and digestion.
The doctor said a bacterium caused the infection.
Scientists discovered a new bacterium in the soil that can break down plastic waste.
While a single bacterium is invisible to the naked eye, rapid reproduction can lead to the formation of visible colonies on a nutrient-rich agar plate within twenty-four hours.
From New Latin bactērium, from Ancient Greek βακτήριον (baktḗrion, “small staff”), from βακτηρία (baktēría).
The word is the singular form; 'bacteria' is the plural form and is much more common in everyday speech.
this bacteria isthis bacterium isLearners often use the plural 'bacteria' with a singular verb. 'Bacterium' is the singular form.