Medical Definition of orthopoxvirus
1 capitalized : a genus of poxviruses that are brick-shaped measuring about 200 by 200 by 250 nanometers, that hybridize extensively within the genus and sometimes with the DNA of members of other poxvirus genera, and that include the vaccina virus and the causative agents of cowpox, monkeypox, mousepox, and smallpox
2: any virus of the genus Orthopoxvirus
Seen and Heard
What made you want to look up orthopoxvirus? Please tell us where you read or heard it (including the quote, if possible).