late 15th century: from French blond, blonde, from medieval Latin blundus 'yellow', perhaps from Germanic
The alternative spellings blonde and blond correspond to the feminine and masculine forms in French, but in English the distinction is not always made, as English does not have such distinctions of grammatical gender. Thus, blond woman or blonde woman, blond man or blonde man are all used. The word is more commonly used of women, though, and in the noun the spelling is typically blonde. In American usage the usual spelling is blond for both adjective and noun.