h₂ŕ̥tḱos
“bear, large predator”bear, predator
PIE word for bear. Gives Latin ursus, Greek árktos, Sanskrit ṛ́kṣa. Germanic replaced it with *berô "the brown one" (taboo avoidance).
Discussion
The PIE noun *h₂ŕ̥tḱos (bear) is perhaps the most famous example of taboo-driven lexical replacement in comparative linguistics — a word so feared that speakers of several daughter languages refused to say it aloud, replacing it with euphemisms that eventually became the standard words for bear in their languages. The story of *h₂ŕ̥tḱos is a story about the power of naming and the belief that to speak a predator's true name was to summon it.
The word survives transparently in the branches that did not enforce the taboo. Greek árktos (ἄρκτος, "bear") continues the PIE form directly and gave English Arctic (arktikós, "pertaining to the bear" — the northern region defined by the constellation Ursa Major, the Great Bear) and Antarctic (the opposite pole, "anti-bear"). Latin ursus (bear), from an earlier *urcsus via rhotacism, preserves the word with regular Italic phonological treatment: Ursa Major and Ursa Minor (the bear constellations), ursine (pertaining to bears). Sanskrit ṛ́kṣa- (bear) confirms the Indo-Iranian reflex.
But in two major branches — Germanic and Slavic — the inherited word was abandoned. The Germanic peoples replaced *h₂ŕ̥tḱos with *berô ("the brown one"), from which English bear, German Bär, and the Scandinavian forms descend. The bear was not called by its name but by its colour — a circumlocution designed to avoid attracting the animal's attention. The Slavic branch went further: Russian medvédʹ (bear) literally means "honey-eater" (from *medhu-, honey, + *ed-, to eat), a flattering description intended to appease the creature by calling it something pleasant rather than something that might provoke it.
The Baltic branch adopted yet another replacement: Lithuanian lokỹs (bear) is of uncertain etymology but is clearly not a continuation of *h₂ŕ̥tḱos.
This pattern of independent replacement in multiple branches points to a widespread cultural prohibition against naming the bear — a taboo that must have been in force already in late PIE or early post-PIE times, given that the replacements are branch-specific rather than shared. The bear was evidently the most feared animal in the PIE speakers' environment: dangerous enough that its very name was considered dangerous.
The phonological complexity of the root — initial laryngeal, syllabic resonant, palato-velar cluster — has made it a challenging reconstruction, but the regularity of the reflexes in Greek, Latin, Sanskrit, and Armenian (arǰ, "bear") confirms the form. Pokorny (IEW 875) treats the root under *r̥tḱo-s, and the laryngeal theory adds the initial *h₂-.
The bear's taboo name is not unique in world languages — many cultures avoid the true names of feared animals, calling the wolf "the grey one" or the tiger "the striped uncle" — but the PIE case is the best documented and most systematically reconstructable. It demonstrates that linguistic change can be driven not only by phonological laws and semantic drift but by fear, by the human conviction that names have power and that some things are better left unnamed.
Notes
Classic example of taboo replacement; cf. "Arctic" from Greek árktos