Winthrop Surname and Variants

English: habitational name from places in Lincolnshire and Nottinghamshire called Winthorpe. The former is named with the Old English personal name or byname Wine, meaning ‘friend’, + Old Norse þorp ‘settlement’. In the latter the first element is a contracted form of the Old English personal name Wigmund, composed of the elements wig ‘war’ + mund ‘protection’, or the Old Norse equivalent, Vígmundr.

Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4