Some of my favourites:
- cephalophore (n) – A Christian saint depicted in artworks as carrying their own severed head.
- eggcorn (n) – A reanalysis of a word or phrase for another that sounds similar and could be taken to have a similar meaning.
- kakistocracy (n) – Rule by the worst and least qualified people.
- nychthemeron (n) – A period of 24 hours, a day and a night.