French term (translation: staircase wit) for when the perfect response, retort, or comeback comes to mind too late.
"His argument left me so speechless that I couldn't clearly think of a response until I reached the bottom of the stairs. Then, l'esprit de l'escalier came to me."
Friend 1: Quick let's take the escalator!
Friend 2: No. Take the escalearlier. We need to get there fast!
Friend 1: Good idea. If we we're not quick they'll think we took the top escalator.
Friend 2: What the hell is that noise?!
Friend 1: Sorry. I was just humadruming.