Definition of Zein:

part of speech: noun

The gluten of maize, a substance of a yellowish colour.

Usage examples:

• 1886. 10. Alaeddin and Zein ul Asnam. Thomas Wright in "The Life of Sir Richard Burton".

• Animals fed on the zein mixture died in a few days but the inexplicable thing was that when the missing tryptophan was added to the diet the animals lived a little longer but finally declined and died. Walter H. Eddy in "The Vitamine Manual".