Unknown is a distinctive girls' name in United States, ranking #2515 in 2014 with 72 recorded births. The name reached its all-time peak in 2009 with 84 births ranking #2334. Since 1996, the popularity has increased by 35.8%. In 2014, approximately 1 in every 24,805 girls born was named Unknown. STABLE Recent data shows the name is currently stable.