The surname Los is a topographic name derived from the Middle Dutch word "lo" which meant 'grove' or 'clearing'. The name was then originally for someone who lived in such a grove or clearing. The Dutch prefix "Van" means 'of' or 'one who lived at' and was often attached to location names to create a surname.
^ Filby, P. William, Meyer, Mary K., Passenger and immigration lists index : a guide to published arrival records of about 500,000 passengers who came to the United States and Canada in the seventeenth, eighteenth, and nineteenth centuries. 1982-1985 Cumulated Supplements in Four Volumes Detroit, Mich. : Gale Research Co., 1985, Print (ISBN 0-8103-1795-8)