Various theories have been proposed for its original meaning:
Qu Wanli, Qiu Xigui and others propose that it originally refers to a type of dancer-musicians. This usage is attested in the oracle inscriptions. This may be supported by ancient literature, e.g. Shijing, which mentions a type of dance called 萬舞／万舞.
Lin Yiguang proposes that it is an ancient form of 丏 (OC *meːnʔ), acting as a phonetic component in 賓 (OC *mpin).
Some propose that it is a differentiated form of 亥.