Unknown is a distinctive boys' name in United States, ranking #4635 in 1998 with 15 recorded births. The name reached its all-time peak in 2009 with 113 births ranking #1484. Since 1996, the popularity has decreased by 71.7%. In 1998, approximately 1 in every 127,421 boys born was named Unknown. FALLING Recent data shows the name is currently falling.