Zidane's signature move. Also called the zidouken

1. The default beliefs installed when you were a child.

2. An unexamined position you absorbed from your environment growing up.

A move used to inflict damage on an object/opponent. You pull your head back and slam it forwards using the part of the skull above the forehead to strike.
Usually you hold your opponents face square with one or two hands and bash them in the nose with your head.
For greater damage you hold their head with your leading hand, raise your leading foot while leaning away, then bring your leading foot back towards them in a stomping motion with the headbutt coming in right behind to gain the momentum of the stamp. This technique is used by wrestlers a lot.
Not to be confused with "butt head".

What a Frenchmen does when he gets angry

Applying a quick and sudden pang to another by thrusting your forehead directly into that of anothers. Often used to gain the upper hand while engaging in a quarrel.

What a Frenchman does when he's really, really angry.

When two men make contact with their penis heads. This is not necessarily a gay thing, but more of a common ground of respect and admiration among male friends. It should be encouraged.