I love this! I had no idea about the Etymological Wordnet and it probably would have saved me a ton of time developing my app for finding "interesting" cognates: https://etymologyexplorer.com

I've always loved the same thing—finding hidden connections between everyday words. I recently did this with "vain". It comes from Latin vanus, meaning "empty". More obvious with the "in vain" meaning, but the modern day comes from the idea of an exaggerated self image, with no substance behind it. It has a ton of "empty" cognates: vanish, evanescence, vanity (table), vaunt, vacuous, vacuum, vacation, void, devastate, wanton, wane