Where does “tối nghĩa” come from?

tối nghĩa (Vietnamese) comes from Vietnamese tối, from Vietnamese tí, from Middle Chinese 子, from Proto-Sino-Tibetan *tsəʔ — child, son, offspring; grandson; relatives; nephew/niece.

tối nghĩa (Vietnamese): difficult to understand; obscure; ambiguous; open to multiple interpretations

Definitions

difficult to understand; obscure; ambiguous; open to multiple interpretations

Ancestry of “tối nghĩa”, step by step

tối nghĩa traces back through two separate lines of ancestry.

via Vietnamese tối

Step	Language	Word	Meaning
1	Vietnamese	tối	dark; the duration from the late evening to the...
2	Vietnamese	tí	breast; a little bit; tiny; small
3	Middle Chinese	子	—
4	Proto-Sino-Tibetan	*tsəʔ	child, son, offspring; grandson; relatives; nephew/niece

via Vietnamese nghĩa

Step	Language	Word	Meaning
1	Vietnamese	nghĩa	a meaning; a sense; morality
2	Chinese	義	—

Every word from Proto-Sino-Tibetan *tsəʔ →Every word from Middle Chinese 子 →Every word from Vietnamese tí →