dʰugh₂-
“to milk, to be productive”milk, yield, produce
Root related to milking/productivity, yielding English daughter (possibly the milker), Old English dugu (virtue).
Discussion
The PIE root *dʰugh₂- (to milk, to be productive, to yield nourishment) may underlie one of the most famous kinship reconstructions in comparative linguistics — the word for "daughter," if Benveniste's analysis connecting *dʰugh₂tḗr (daughter) to "the milker" is correct.
Sanskrit dúhati ("he/she milks") and the related dógdhi ("she milks") preserve the verbal root transparently. The milking of cows was a fundamental daily activity in the PIE pastoral economy, and the vocabulary reflects this centrality.
If the daughter-milker connection holds, *dʰugh₂tḗr literally means "the milking one" — the daughter defined by her role in the household economy rather than by biological descent. This parallels *suHnús (son — from *sewH- "to give birth," the born one) in defining children by function rather than mere kinship.
The root connects to the broader PIE dairy vocabulary: *gʷṓws (cow — the source of milk), *mélit (honey — the other sweet substance), and *h₃éwis (sheep — also milked). The PIE speakers were a dairy people, and their kinship terminology may have encoded the labour roles that sustained their pastoral economy.
Notes
Pokorny 271. The daughter connection is debated.