/in ˈvēvō/
Adjective or Adverb
1. Experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro (“within the glass”, i.e., in a test tube or petri dish) controlled environment. (wikipedia.org)
2. Within a living organism. (wiktionary.org)
3. Of a biological process occurring within a living organism. (wordnetweb.princeton.edu)
4. In the living body of a plant or animal. (merriam-webster.com)
Word origin: Latin; “within a living organism.”