Meaning and Name Origin
Brennan \b-rennan, br(en)-nan\ as a boys' name (also used less commonly as girls' name Brennan) is pronounced BREN-an. It is of Irish and Gaelic origin, and the meaning of Brennan is "teardrop". Variant of Brendan.
For more on this name, see also the related boy name Brandon.
Brennan has 1 feminine form: Brenna.
Brennan is a rare given name for males but a very popular surname for all people (#744 out of 88799, Top 1%). (2000 U.S. Census)
Charted below is the baby name popularity of Brennan for boys. Brennan was first listed in 1970-1979 and reached its highest position of #243 in the U.S. in the year 2009, and is at #386 presently. (2014 Birth Statistics)
Below is a charted analysis of the popularity of the boy name Brennan and associated names. Prominent variation forms of Brennan (#386 in 2014) appearing in the Top 1000 are Brandon (#71 in 2014), Brendan (#351), Brenden (#711), Brendon, Brennen and Brennon. These boy names reached the peak of their popularity in the year 1998 and have become much less widespread since, with the versions Brenden, Brendon and Brennen becoming less in vogue. Brandon (#71), Brendan (#351) and Brennan (#386) are three of the more chic birth names in this compilation. (2014 Birth Statistics)