The uncontrollable urge to cough whenever a little bit of smoke enters the room. Usually occurs after one person starts and often infects the entire room.
When someone is craughing, it is near impossible to tell if they are crying or laughing. Normally the craugher is in another room or out of eyesight, so you can't see their crying/laughing face.
Note: Not to be confused with craffing, the act of crying and laughing at the same time. Craughing is when you can't tell between the two.