Catch A Train Edit Meaning

1.

A phrase used between two people who know it to tell one another when they need to take a shit. It is only used in the presence of people who you don't want to know that you have to take a shit. You can add adjectives to this phrase to describe the current situation. See below

Normal - "Hey dude, I gotta go catch a train, I'll see you later"

One that is about to come out - "Brady, I just remembered that I have to catch a train with my brother, and I'm runnin way late. I gotta run!"

See phrase, down low, quiet, shit