- Proto-Sino-Tibetan: ?
- Proto-Tibeto-Burman: *m-lawŋ (Matisoff, STEDT); *m-loŋ (Matisoff, 2003); *(m-)loŋ (Benedict, 1972; Weidert, 1987)
Old Chinese had two words for “boat”:
- 舟 (), ultimately from *tjɯwProto-Mon-Khmer *ɗuuk ~ *ɗuk (“boat, canoe”). It occurs in Shang bronze inscriptions and was commonly used in central and eastern China.
- 船 (), from this PTB root, is only found in later texts and by Han times had completely replaced the previous synonym. It was used in western China. *ɦljon
The latter character is interpretable as a nominal derivative of the verb 沿 (, “to go downstream a river”) (Sagart, 1999). However, an alternative proposal about the origin of PTB *m-lawŋ has been advanced by Sidwell (2006) and Schuessler (2007). They regard it as area word of Austroasiatic descent, possibly from *lonProto-Mon-Khmer *d₂lu(u)ŋ ~ *d₂l(u)əŋ (“boat”), whence Mon ဂၠုၚ် (klɜ̀ŋ, “canoe, small boat”). The PMK root may in turn be a deverbal noun from Proto-Mon-Khmer *luŋh ~ *luuŋh ~ *ləŋh (“to hollow, excavate, bore”); compare Khmer លុង (lung, “to dig a hole”) and Vietnamese trũng (“concave”). This aligns with the fact that, according to the Yijing, ancient Chinese canoes were originally hollowed tree trunks. Compare also Burmese လှိုင်း (hluing:, “uneven surface”) and Mizo lawng (“to take out the heart of a wild plantain tree”).
For a similar root in Southeast Asia see also Proto-Austronesian *ʀuqaŋ (“hole, pit”), whence Tagalog guang (“gap, hole”) and Malay ruang (“hollow space; ship's well”); and Proto-Austronesian *luaŋ (“hole in the ground”), whence Tongan luo (“pit, depression”) and Samoan lua (“hole”) (Sidwell, 2006; Blust, ACD).
- Old Chinese: 船 /*Cə.lon/ (B-S), /*ɦljon/ (ZS) ("boat, ship")
- *looŋ (“boat, ship, vessel”) (VanBik, 2009)