Karate

Funakoshi Gichin, one of the creators of
modern karate.
The word 唐手 "karate" means "only hand" or "empty hand". Karate is perhaps most known Japanese martial art. It is originated from Okinawa. Karate's Southern Chinese origins are well known. It is a strange combination of Chinese boxing kung-fu and Japanese techniques. Karate's fundamental techniques are uchi (arm strikes) tsuki (thrusts) and keri (footwork).
Comparing to aikido and judo, the essential idea of karate is very different as arm strikes and kicks are present. For each offensive movement there is defensive counter move.
Karate is competition oriented martial art. There are two types of karate competition, kata comptetition, and kumite. Kata competition is based on choreographed series of kata (move), and kumite is sparring match, similar to judo, in which karateka get point for each punch, thrust or kick executed correctly, with style.
"The ultimate aim of Karate lies not in victory or defeat, but in the perfection of the character of its participants." -- Gichin Funakoshi
"The Way is not meant as a way of fighting. It is a path on which you travel to find your own inner peace and harmony. It is yours to seek and find." -- Hironori Ohtsuka
Few other related Japanese words:
空手道 "karate-dō" the "do" suffix means modern karate
基本 "kihon" the study of the fundamental techniques of karate