When Petrus N. Demarest was born on 12 October 1763, in Bergenfield, Bergen, New Jersey, United States, his father, Niclaes ‘Nicholas’ Demarest, was 39 and his mother, Elsie Demarest, was 40. He married Marie Brouwer on 16 November 1792, in Tappan, Orangetown, Rockland, New York, United States. They were the parents of at least 3 sons and 4 daughters. He died on 26 March 1837, at the age of 73, and was buried in Nanuet, Clarkstown, Rockland, New York, United States.
French: regional variant of Demarais , a cognate of 2 below.
Altered form of French Desmarets: habitational name, with fused preposition and definite article des ‘from the’, for someone from any of various places called Les Marets (from a regional derivative of Old French mareis ‘marsh’). Alternatively, the name may simply have been topographic. Compare Demaray , Demaree , and Demorest .
History: The progenitor of many of the American Demarests was David Demarest from France, who settled in NY (and later in NJ) in the second half of the 17th century. His father's surname was DesMarets. David Demarest is listed in the (US) National Huguenot Society's register of qualified Huguenot ancestors (as David Demarêts or Demarest or des Marêts or des Marest) and also in the similar register of the Huguenot Society of America (as David des Marest).