Reconstruction:Proto-Sino-Tibetan/s-twak

Etymology
This root is well-attested in Lolo-Burmese and other branches of the family however in some languages it has been specialized to refer to animal births. The -t final is particular to Chinese, but this could well be a secondary development from an original velar after a front vowel. This term may have been conflated with a descendant from – whence the  – a sense no longer productive but was mentioned in the glossary book ,.
 * Proto-Sino-Tibetan: *s-twak (STEDT)

Noun

 * 1) go out
 * 2) leave
 * 3) emerge

Descendants

 * Old Chinese: ("go out; leave")
 * Modern Mandarin
 * Beijing: ("go out; leave") (chū)
 * Lolo-Burmese-Naxi
 * Lolo-Burmese
 * Burmish