Quick answer
Nash is a boy name meaning "at the ash tree".
Meaning and history
From an English surname that was derived from the Middle English phrase atten ash "at the ash tree". A famous bearer of the surname was the mathematician John Nash (1928-2015). As a given name for boys, it gained some popularity in the mid-1990s after the debut of the American television series Nash Bridges. It got more exposure beginning 2005 when a character by this name started appearing on the soap opera One Life to Live.
Notes and context
Usage: english