Dex is a distinctive boys' name in United States, ranking #4859 in 2011 with 19 recorded births. The name reached its all-time peak in 2016 with 43 births ranking #2796. Since 1996, the popularity has increased by 137.5%. In 2011, approximately 1 in every 99,947 boys born was named Dex. FALLING Recent data shows the name is currently falling.