Cahill
An Irish surname from the old personal name Cathal, meaning “battle rule” or “strong in battle.”
The #1,737 most common surname in the United States (2010 Census) — about 1 in every 14,971 Americans shares it.
Etymology
Cahill is an anglicized Irish surname from Mac Cathail or O Cathail, built on the personal name Cathal. The old name is usually explained from elements meaning “battle” and “rule,” so the sense is roughly “battle leader” or “powerful in battle.” Older writers sometimes gave related but looser explanations, but the Cathal derivation is the standard one.
History
The surname is well established in Ireland, especially in western and central areas, and later spread widely through emigration. It often appears in records in forms such as MacCahill, O'Cahill, and Cahill. Modern bearers include many Irish-American families, and the name is common enough in the United States to be familiar but not among the most frequent surnames.
Origin
Regions
Variant spellings
Fun fact
Some 19th-century writers tried to connect Cahill with other Irish-looking forms, but the surname is now generally treated as coming from the personal name Cathal.
From the historical record
“of corc, a knife] MAC HALE I for Mac Cahill (Celt.) Son of Cathal: v. Cahill. 2 the Irish Mac HHl,'Sa.\A (as, to the main name) to be of Anglo-Norman origin. Dr. Mac Hale, Archbishop of Tuam,”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)