One of the three characters (無/无, 无, 亡) that have historically been used to represent the word "no, not any". First attested in the Warring States period; used interchangeably with 無/无 until the Tang dynasty. Readopted by the PRC in 1956.
The origin of this character is unknown. Probably an ancient variant form of either 元(yuán), 天(tiān) or 堯/尧(yáo). This character must not be confused with 旡.
For pronunciation and definitions of 无 – see 無 (“to nothave something; there is not ...; etc.”). (This character, 无, is the simplified and variant form of 無.)
Notes:
Simplified Chinese is mainly used in Mainland China, Malaysia and Singapore.