Latinized form of a Celtic name (or title) that possibly meant either “king, prince” or “raven”. Brennus was a Gallic leader of the 4th century BC who attacked and sacked Rome.
From an Irish surname derived from Ó Braonáin meaning “descendant of Braonán”. Braonán is a byname meaning “rain, moisture, drop” (with a diminutive suffix).
From Brendanus, the Latinized form of the Irish name Bréanainn, which was derived from a Welsh word meaning “prince”. Saint Brendan was a 6th-century Irish abbot who, according to legend, crossed the Atlantic and reached North America with 17 other monks.
Possibly a feminine form of the Old Norse name Brandr, meaning “sword”, which was brought to Britain in the Middle Ages. This name is sometimes used as a feminine form of Brendan.