自摸

Verb

 * 1)  to self-draw the winning tile
 * 2)  to masturbate; to touch oneself
 * 1)  to masturbate; to touch oneself

Usage notes

 * When playing mahjong, a player may say this word as a call for such a win.

Etymology 1
Shift from tsūmō (see Etymology 2 below).

Now the more-common reading, likely due to the rise of mahjong video games during the later half of the 20th century.

Noun

 * 1)  self-drawing the winning tile; also, a call for such a win
 * 2)   a  of self-draw and all closed melds, worth 1

Etymology 2
From.

Noun

 * 1)  self-drawing the winning tile; also, a call for such a win