Meaning :brennan as a girl, the name is used (also, more in general, as a young man by the name brennan), is of irish or gaelic origin, and the meaning of brennan is "descendant of braonán". transferred use of the surname. braonán is a personal name meaning "moisture, drop" or may also be a contracted form of brendan.,brennan as a boy's name (also less often than the names of girl brennan) is very bren-a. he is irish gaelic and the origin, and the meaning of brennan is "teardrop". variant of brendan. also in the form of brandon.,a descendant of the sad,the life of the beacon,shaped like a teardrop, the sadness,teardrop-shaped
