Laughter
Issaac is a rare spelling variant of the Hebrew name Isaac. It is derived from the name Yitzchaq, which literally translates to 'he will laugh,' referencing the biblical story of Sarah's reaction to the news of her pregnancy.
Less common today
Issaac isn't in the latest US Top 1000. It last peaked at #6,179 in 1990.
US births per 5-year period, 1990βpresent (SSA data).