Aikido: The art of unity with the ground, the way of blending energy. The aikidoka (one who practices aikido) attempts to become one with the mat by being thrown into it repeatedly in the hope that s/he will merge with the mat. This usually doesn't happen, so the process must be repeated. Frequently.
Kiai-do: Dyslexic Aikido. Also known as "drunken Aikido", this is usually practiced in bars, accompained by much shouting.
Ukemi: The art of blending with the mat - part of what aikidoka study. The art of hurling yourself at the Earth for no good reason.
Nage-waza: The art of helping others to blend with the mat - the other part of what aikidoka study.
Shodan (male): A male who is so adept at blending (and helping others to blend) that he can wear a skirt to class and nobody in class will laugh at him because he might help them learn to blend with the mat. At high velocity.
Hakama: what shodans call a skirt so they don't have to teach quite as many people to blend with the mat (see shodan (male)).