Dex is a distinctive boys' name in United States, ranking #7198 in 2010 with 11 recorded births. The name reached its all-time peak in 2016 with 43 births ranking #2796. Since 1996, the popularity has increased by 37.5%. In 2010, approximately 1 in every 174,401 boys born was named Dex. FALLING Recent data shows the name is currently falling.