Where does “cavity” come from?

cavity (Middle English) comes from Middle French cavité, from Latin cavitas, from Latin cavus, from Proto-Italic kawos, from Proto-Indo-European ḱowh₁ós, from Proto-Indo-European ḱewh₁- — to swell; to be strong.

Ancestry of “cavity”, step by step

StepLanguageWordMeaning
1Middle Frenchcavité—
2Latincavitascavity
3Latincavushollow, concave; excavated, channeled;...
4Proto-Italickawos—
5Proto-Indo-Europeanḱowh₁óshollow
6Proto-Indo-Europeanḱewh₁-to swell; to be strong
Every word from Proto-Indo-European ḱewh₁- →Every word from Proto-Indo-European ḱowh₁ós →Every word from Proto-Italic kawos →