Meaning & Definition of word "Bacterium"

noun:

• 1. A singular form of bacteria; a microscopic single-celled organism that can exist either independently or as a parasite.
  • Example: The bacterium responsible for the infection was identified as Staphylococcus aureus.
• 2. A unicellular microorganism that can be found in various environments, known to play critical roles in ecosystems and human health.
  • Example: The soil bacterium helped in the decomposition of organic matter.
• 3. An organism classified as a prokaryote, which lacks a membrane-bound nucleus.
  • Example: Scientists studied the bacterium to understand its resistance to antibiotics.
• 4. Any of a large group of bacteria, some of which can cause diseases in animals and humans.
  • Example: The child was diagnosed with an illness caused by a pathogenic bacterium.
• 5. A single bacterium cell, often used in scientific research and microbiology.
  • Example: They observed the behavior of a single bacterium under the microscope.