Isiac is a distinctive boys' name in United States, ranking #10264 in 2009 with 7 recorded births. This places Isiac in the bottom 29% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2001 with 15 births ranking #4979. In 2009, approximately 1 in every 283,329 boys born was named Isiac. STABLE Recent data shows the name is currently stable.