| Yama-arashi: | Mountain storm. Hand technique | |
| Yang: | “Active” or “positive.” In ying-yang theory, the positive aspect associated with what is described as centrifugal, expansive and extroversive. | |
| Yari: | Spear. | |
| Yikwon: | Backfist. | |
| Yin: | “Passive” or “negative.” One of the fundamental metaphysical elements of yin-yang whose balance is believed to be the center of existence. | |
| Yo: | Same as Yang in Yin-Yang | |
| Yodan: | 4th degree black belt in traditional Japanese styles. | |
| Yojimbo: | “Bodyguard.” The name given to a masterless samurai (ronin) who hired themselves out as professional bodyguards. | |
| Yoko: | “Side” or “lateral.” | |
| Yoko aruki: | One of the unique ninja walking techniques to move stealthily through woods or narrow areas. | |
| Yoko-geri: | Side kick | |
| Yoksudo: | Ridge hand. | |
| Yokosutemi-waza: | Side sacrifice techniques | |
| Yon sok: | Combination. | |
| Yubi: | Finger. | |
| Yudansha: | 4th degree black belt |
