Definition:
Naches is a Yiddish word that means "pride" or "joy." Typically naches refers to the pride or joy that a child brings a parent. For instance, when a child is born people will often say to the new parents "May [your son or daughter] bring you naches." The "ch" is pronounced gutturally - so it's not "ch" as in "cheese" but rather "ch" as in "Bach" (the composer).
Examples:
You bring me such naches!