Norse linguistics is great. The word for fear/dread was Uggr pronounced Ug. Fearsome or dreaded was Ugsome. To be feared was Ugligr with -ligr meaning -like which became -ly. So ugly was to be feared lol

There's also great ones in Gaelic. Like the translation of cat into Scottish Gaelic is cat, it's a loan word. The word for kitten is piseag. So some trader brought them cats and by the time they had kittens there was no one to ask what they were called.