| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
virulence vir·u·lence (vēr'yə-ləns, vēr'ə-)
n.
The quality of being poisonous.
The capacity of a microorganism to cause disease.
The capacity of a pathogen, such as a microorganism or toxin, to produce disease.
Note: “Virulent” substances or organisms are extremely pathogenic or toxic.