ceathair (Irish)
Where does "ceathair" come from?
The Irish word 'ceathair', meaning four, traces its lineage back to the ancient Proto-Indo-European root *kʷetwóres. From there, it evolved into Proto-Celtic as *kʷetwores before being inherited by Old Irish as 'cethair', eventually settling into its modern form.
Full etymology tree
- ceathair (Irish), 'four'
- inherited cethair (Old Irish), 'four'
- inherited *kʷetwores (Proto-Celtic), 'four'
- inherited *kʷetwóres (Proto-Indo-European), 'four'
- derived *kʷet- (Proto-Indo-European)
- derived *kʷetu- (Proto-Indo-European)
- inherited *kʷetwóres (Proto-Indo-European), 'four'
- inherited *kʷetwores (Proto-Celtic), 'four'
- inherited cethair (Old Irish), 'four'
Ancestors
- cethair (Old Irish)
- *kʷetwores (Proto-Celtic)
- *kʷetwóres (Proto-Indo-European)
Descendants and derived words
- ceathrú (Irish)
- ceathrú (Irish)
Updated July 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris