octo (Latin)

Where does "octo" come from?

The Latin numeral 'octo', meaning 'eight'[1], was inherited from Proto-Italic '*oktō'[1], which itself derived from Proto-Indo-European '*oḱtṓw'[2]. Related terms appear across the Indo-European language family, including Sanskrit 'अष्ट', Ancient Greek 'ὀκτώ', Gothic '𐌰𐌷𐍄𐌰𐌿', and Old English 'eahta'. Scholars have suggested that the ancient form may have originally stemmed from a prehistoric dual concept representing two times four fingertips in an early base four counting system[1].

Open questions

• The theory that the form stems from a Proto-Indo-European dual meaning two times four fingertips in a base four system is a scholarly proposal. [1]

Full etymology tree

• octo (Latin), 'eight; 8'
  • inherited *oktō (Proto-Italic), 'eight'
    • inherited *oḱtṓw (Proto-Indo-European), 'eight'

Cognates and doublets

• ὀκτώ (Ancient Greek)
• 𐌰𐌷𐍄𐌰𐌿 (Gothic)
• eahta (Old English)
• अष्ट (Sanskrit)

Descendants and derived words

• octuplus (Latin)

Sources

1. octo (Latin) - Wiktionary
2. oktō (Proto-Italic) - Wiktionary

Updated September 2026

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Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris