Isaak is the German, Dutch and Russian spelling of Isaac, the Hebrew Yitzchak, which means "he will laugh" or "laughter", after Sarah laughing when she was promised a son in old age. The k-spelling is standard in central and eastern Europe and gives the patriarch's name a slightly more international look. Isaak entered the American top 1,000 at number 1,000 in 2000, peaked at number 800 in 2001 and has slipped back to number 2,693 in 2025, with 48 births, while Isaac itself remains a top 100 staple.