Named after the Nostrand family, perhaps after Gerret Noorstrandt in particular.
The family descended from Hans Hansen, a 17th-century settler from the island of Norstrand, now in Germany; his children took the island’s name. NYC Parks says the avenue may be named specifically for his son Gerret. Originally called Nostrand Lane, it has been open since 1840; in 2004, the 200th anniversary of Haiti’s independence, it was co-named Toussaint Louverture Boulevard.