Thames (English)

Where does "Thames" come from?

The English name Thames traces its roots through Middle English 'Temese'[1][4] and Old English 'Temes'[1][5] back to the Latin 'Tamesis'[1][2], which was borrowed from Proto-Brythonic '*Tamesis'[1][2]. This ancient name stems from Proto-Celtic '*tamesās', meaning 'river' or 'waters' with a literal sense of 'darkness'[1]. This Celtic form descends from the Proto-Indo-European root '*temH-', meaning 'dark'[1][3]. During the Middle English period, the spelling acquired an 'h' due to the mistaken assumption of a Greek etymology[1]. Alternative theories suggest the name may derive from a Proto-Celtic root meaning 'to melt' or 'to flow', or potentially from an unknown non-Indo-European root[1].

Open questions

• The etymology may alternatively derive from a Proto-Celtic root meaning to melt or flow, or from an unknown non-Indo-European root. [1]

Full etymology tree

• Thames (English), 'A river in southern England, flowing 336 km (209 mi.) from Gloucestershire, through Wiltshire, Oxfordshire, Berkshire, Buckinghamshire, Surrey and Greater London, and between Essex and Kent to the Thames Estuary and North Sea.'
  • inherited Temese (Middle English), 'The Thames (river in SE England, notably having London on its bank)'
    • inherited Temes (Old English), 'the River Thames'
      • inherited Tamesis (Latin), 'the Thames (a river in Britain that runs through London)'
        • inherited *Tamesis (Proto-Brythonic)
          • derived *tamesās (Proto-Celtic)
            • derived *tm̥Hes- (Proto-Indo-European)
              • derived *temH- (Proto-Indo-European), 'dark'

Ancestors

• Temese (Middle English)
• Temes (Old English)
• Tamesis (Latin)
• *temeslos (Proto-Celtic)
• *teh₂- (Proto-Indo-European)

Cognates and doublets

• dobhar (Irish)
• Tamaris (Latin)
• Tamarus (Latin)
• Tâmega (Portuguese)
• *dubros (Proto-Celtic)
• *dʰubʰrós (Proto-Indo-European)
• तमसा (Sanskrit)
• dŵr (Welsh)
• Tafwys (Welsh)
• Teifi (Welsh)

Descendants and derived words

• Thamesmead (English)
• Abingdon-on-Thames (English)
• cross the Thames (English)
• Dorchester-on-Thames (English)
• Goring-on-Thames (English)
• Henley-on-Thames (English)
• Kingston upon Thames (English)
• Moscow-on-Thames (English)
• Purley on Thames (English)
• Richmond upon Thames (English)
• Sandford-on-Thames (English)
• set the Thames on fire (English)

Sources

1. Thames (English) - Wiktionary
2. Tamesis (Latin) - Wiktionary
3. temeslos (Proto-Celtic) - Wiktionary
4. Temese (Middle English) - Wiktionary
5. Temes (Old English) - Wiktionary
6. témHos (Proto-Indo-European) - Wiktionary

Updated August 2026

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