Yaai: to attack stepping down
Yaai Hau Gurk: to attack by stepping down on the opponents rear leg
Yaai Sut: to attack down with the knee
Yaan Geng or Daai Geng: guiding power
Yang: everything that is strong, light, active male, etc
Yang Chi: the energy you inhale from air; oxygen
Yap Jung Lou: closing the gap
Yau: to relax; an essential principle of the Siu Lim Tao form
Yee Gee Kim Yeung Ma: the mother of all stances; the stationary front stance for developing all stances which means two knees going in stance
Yee Ma: transitions between the stances in the pole
Yee Ying Bo Sau: using your structure to recover your position
Yim Wing Chun: the you lady that Ng Mui taught with Wing Chun system to. She further refined and improved the system so it is named after her.
Yin: everything that is weak, dark, quiet, female, etc.
Yin and Yang: a pair of opposites that constantly change. All things have both yin and yang and all things change.
Yin Chi: energy you exhale or carbon dioxide
Ying: structure
Yip Man: the late grandmaster of Wing Chun who taught publically which spread the system
Yon Geng: elastic power
Yuen Geng: patience energy also the ability to make the opponent move the way you want
Yut Bo: turning around stance in the knife form with fak do and also going through the legs with knives
Yut Ge Chon Kuen or Doi Kou Kuen: vertical punch