Where does “ủ rũ” come from?

ủ rũ (Vietnamese) comes from Vietnamese U, from Portuguese u, from Old Portuguese u, from Latin ubi, from Latin cubi, from Latin cubus, from Ancient Greek κύβος — square; cube; die, dice.

ủ rũ (Vietnamese): sullen; gloomy; melancholy

Definitions

sullen; gloomy; melancholy

Ancestry of “ủ rũ”, step by step

ủ rũ traces back through two separate lines of ancestry.

via Vietnamese U

Step	Language	Word	Meaning
1	Vietnamese	U	—
2	Portuguese	u	u; where; Eye dialect spelling of o
3	Old Portuguese	u	where
4	Latin	ubi	where? in what place?, in which place?; "When" or...
5	Latin	cubi	nominative plural of cubus; genitive singular of...
6	Latin	cubus	A mass, quantity; A cube
7	Ancient Greek	κύβος	square; cube; die, dice

via Vietnamese rú

Step	Language	Word	Meaning
1	Vietnamese	rú	forest, woods; mountain; mountainous areas
2	Old French	rue	rue (plant)
3	Latin	rūga	a crease in the face, wrinkle
4	Proto-Indo-European	krewp-	scab, crust; to become encrusted
5	Proto-Indo-European	krew-	to fall, collapse; scab; to fall, break, bruise

Every word from Ancient Greek κύβος →Every word from Latin cubus →Every word from Latin cubi →