κάρυον

Of unclear origin.

Traditionally compared with Latin carīna (“ship's keel; shell of a nut”) and Sanskrit करक (karaka, “water jar; coconut (shell)”). The Latin term is likely cognate, though whether via borrowing from Greek, a common third source, or via inheritance (traditionally taken as Proto-Indo-European *ker- (“hard”), whose existence has been doubted, including by Beekes) is uncertain, while the Sanskrit term is more dubious, particularly as the "coconut shell" meaning is listed as lexicographic, indicating that it may not have been the primary meaning.

Based on the Hesychian variant ἄρυα (árua, “Heraclitean nut”) displaying a κ (k) / ∅ interchange in the initial, Beekes takes the word as Pre-Greek.^[1]

An alternative theory derives the word from Proto-Indo-European *ḱerh₂- (“head”). Cognates include English harns, Old Norse hjarni, Latin cerebrum (all meaning “brain”) and Avestan 𐬯𐬁𐬭𐬀 (sāra), Persian سر (sar) and Sanskrit शिर॑स् (śíras) (all meaning “head”). Also compare κρᾱνῐ́ον (krānĭ́on, “skull”), κέρᾰς (kérăs, “horn”) and κᾰ́ρᾱ (kắrā, “face”). (Can this⁽⁺⁾ etymology be sourced?)

κᾰ́ρῠον • (kắrŭon) n (genitive κᾰρῠ́ου); second declension

1. nut (hard-shelled seed)

• “κάρυον”, in Liddell & Scott (1940), A Greek–English Lexicon, Oxford: Clarendon Press
• “κάρυον”, in Liddell & Scott (1889), An Intermediate Greek–English Lexicon, New York: Harper & Brothers
• κάρυον in Bailly, Anatole (1935), Le Grand Bailly: Dictionnaire grec-français, Paris: Hachette
• κάρυον in Trapp, Erich, et al. (1994–2007), Lexikon zur byzantinischen Gräzität besonders des 9.-12. Jahrhunderts [the Lexicon of Byzantine Hellenism, Particularly the 9th–12th Centuries], Verlag der Österreichischen Akademie der Wissenschaften
• Woodhouse, S. C. (1910), English–Greek Dictionary: A Vocabulary of the Attic Language‎^[1], London: Routledge & Kegan Paul Limited.
  • nut idem, page 563.
  • walnut idem, page 961.