In vitro fertilization is usually defined as taking place outside of the body. That is not what it means, however. In vitro means “in glass.” As in, inside a test tube, assuming the test tube isn’t made of plastic.
The Latin noun vitrum, meaning “glass,” has given rise to a number of English words. Vitreous means “glass-like.” A vitrine is a glass cabinet. Vitrify means to turn something into glass. The vitrifier heats a substance until it melts and then cools it quickly, whereupon it becomes glass-like. Clay, undergoing vitrification, becomes ceramic.
Pardon a digression here about the suffix -ify. Its root is the Latin verb facere, which means “to make.” To satisfy is “to make enough.” To verify is “to make true.” To clarify is “to make clear.” Hence, vitrify, “to make glass.” Have fun making your own list of -ify words.
You might be wondering if vitriol, another word prevalent in our news, has something to do with glass. It does, though not what I was expecting. I guessed that the word might relate to the sharpness of broken glass.
Instead, in its earliest meaning, vitriol is an actual glass-like substance. Chemicals such as copper sulfate can be found in the form of small crystals, which resemble broken glass, in the bottom of mines. The -ol suffix is a diminutive: vitreolus means “little glass” in Latin. Sulfuric acid earned the name oil of vitreol, because it served as an agent to create this change.
Our terms vitriol and vitriolic relate to this acidic meaning: caustic and burning, just like sulfuric acid.
Babies, by the way, who are not conceived in glass are formed in vivo, or “inside the living.” This Latin root also gave rise to vivacity, vivid, convivial, and many others. We shall pass over vivisection.