bấc
See also: Appendix:Variations of "bac"
Vietnamese
editEtymology
editIt is not clear which was the original sense, although it is obvious they are of the same etymology. Compare Chinese 燈心草/灯心草 (dēngxīncǎo, “rush”) and 燈芯/灯芯 (dēngxīn, “wick”).