Etymology of Go
In Chinese, wei 圍 means "to surround" and qi 棋 (see ki character) means "pieces (of a board game)" (a term also used for Xiangqi, Fangqi and many other forms of Chinese board games); weiqi is thus "the game using pieces to surround".
囲 is the Japanese simplification of 圍. It is used in conjunction with the go character 碁 (棋, 棊 and 碁 are 異體字 (itaiji), variations of the same character) to refer to the game in Japanese.
See also names for go in other languages.