• Webster's Revised Unabridged Dictionary
    • n Ureide (Chem) Any one of the many complex derivatives of urea; thus, hydantoin, and, in an extended dense, guanidine, caffeine, et., are ureides.
    • ***
Century Dictionary and Cyclopedia
    • n ureide A compound of urea with an acid radical. The ureides include a large number of urea-derivatives of very complex structure.
    • ***