自摸

zìmō
  1. (mahjong) to self-draw the winning tile
  2. (slang) to play with oneself; to masturbate

CEDICT

slang

Entry Composition

1 自 zì
  1. (bound form) self; oneself
  2. from; since
  3. naturally; as a matter of course
2 摸 mō
  1. to feel with the hand
  2. to touch
  3. to stroke
  4. to grope
  5. to steal
  6. to abstract