Decimus is a distinctive boys' name in United States, ranking #9022 in 2018 with 8 recorded births. This places Decimus in the bottom 36% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2006 with 8 births ranking #8902. In 2018, approximately 1 in every 226,934 boys born was named Decimus. RISING Recent data shows the name is currently rising.