Riboflavin

noun

1. An orange-yellow crystalline compound, C17H20N4O6, the principal growth-promoting factor in the vitamin B complex, naturally occurring in milk, leafy vegetables, fresh meat, and egg yolks.
2. Yellow or orange-yellow water-soluble compound, a member of the vitamin B complex, that acts as a growth-promoting factor in humans and other animals.
3. a B vitamin that prevents skin lesions and weight loss