Definition: (1) later knowledge; (2) wisdom or knowledge that comes after an event, usually too late
Example: A few hours after the argument had ended James hit upon the perfect piece of afterwit.
Rarity: Extremely rare, bottom 20% of words (Merriam-Webster)
Etymology: after + wit, late 16th century.
Across languages: French: esprit de l’escalier; German: Treppenwitz
Why I like this word: This word is both very rare and extremely useful; often in life one realizes something too late. Furthermore, it is the best translation for the German, Trappenwitz, (literal: staircase wisdom), a word sometimes toted as “untranslatable.” Perhaps, those that believed Trappenwitz had no one word English translation will now be experiencing afterwit.