thi ‧ am ‧ in BrE AmE , thi‧a‧mine /ˈθaɪəmiːn, -mɪn/ noun [uncountable]
[ Date: 1900-2000 ; Language: Greek ; Origin: theion 'sulfur' + English -amin (as in vitamin ) ]
a natural chemical in some foods, that you need in order to prevent particular illnesses