stairway wit
'Stairway wit', or 'stairwit', isn't really English, just the direct translation of the French 'l'esprit d'escalier' (originally coined by Diderot) and its German equivalent 'Treppenwitz'. Dutch doesn't have a word for this either, the familiar situation of thinking of what you should have said too late, that one brilliantly witty reply or comeback that would've had the whole room roaring with laughter, but which will never be expressed because you're already on your way out, on the stairs down...
There's a blog collecting them - not all of them that funny, but the frustration of witnessless wit seems to be universal. Good to have a word for such things.
Via: Annelies Verbeke in today's NRC.