Sysum Family History
Sysum Surname Meaning
Apparently from an unidentified place-name suggested by the 1381 form. But if the apparent short vowel in the first syllable of this is misleading then possibly a nickname from Middle English sisamie ‘sesame’ or rather from a related form without the final syllable (perhaps perceived as a dispensable suffix).
This word has the appropriate long vowel in the first syllable.
Source: The Oxford Dictionary of Family Names in Britain and Ireland, 2016
