h₂eyg-
“goat, shame”goat, shame
Root for goat, yielding Greek aix/aigos (goat), English aegis.
Discussion
The PIE root *h₂eyg- presents a debated dual meaning: "goat" and possibly "shame" or "disgrace." The connection between the two senses, if they share a single root, may pass through the concept of the scapegoat — the goat burdened with communal shame and driven out.
Greek aíx (αἴξ, genitive aigós, "goat") is the primary reflex for the animal sense, giving English aegis (originally a goatskin shield — Zeus's protective goatskin, later any protective authority: "under the aegis of"). The Aegean Sea may be named from aíx through a different chain.
Latin possibly preserves the root in a different semantic register, though the connections are debated.
The pastoral significance is clear: goats were one of the PIE speakers' domesticated animals, alongside cattle (*gʷṓws), sheep (*h₃éwis), and horses (*h₁éḱwos). The goat occupied a lower status than cattle in most IE pastoral hierarchies, which may explain the shame-connection: the goat as the lesser animal, the scapegoat as the creature that carries away disgrace.
The word tragedy (Greek tragōidía, "goat-song" — from trágos "goat" + ōidḗ "song") connects Greek drama to goat-ritual, though trágos may be from a different root. The association of goats with both ritual and disgrace pervades IE culture.
Notes
Pokorny 13. English aegis (goatskin shield of Zeus).