The word philtrum has 2 main meanings:
1: noun. The little groove between the bottom of your nose and your top lip. I have no clue what it is there for, but now you know what it is called.
2: verb. The art of performing oral sex while shaving. This originated because some kid at my school with a dirty mind thought it was 'full trim'. The term has since caught on and is now widely recognised.
1: You:"hi Steph! How you been?
Steph:"philtrum" *pokes your philtrum. walks away*
2: You:"hey sweety!"
Boyfriend:"her my giiiirl. Guess what I learnt today?"
You:"what?"
Boyfriend:"how to philtrum"
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.