The name Issac is a boy's name of Hebrew origin meaning "laughter". Issac is ranked #604 on our popularity charts and is often added to user-created lists like Aspens list and discussed in our forums with posts like "A brother or sister for little Jack or Olivia".
From the experts:
A play on the spelling of Isaac that's somehow been in the Top 1000 every year since 1880. (If only by a hair: In both 1926 and 1962, it came in at number 999.) It hit an all-time peak at Number 377 in 2007, and has slumped a fair bit in the ensuing decade.