One of the B-complex vitamins

• A B vitamin
• Vitamin H
• B-complex vitamin
• A B vitamin that aids in body growth
• Vitamin in yeast and liver

Wikipedia Word definitions in Wikipedia
Biotin is a water-soluble B-vitamin ( vitamin B ), formerly known as vitamin H or coenzyme R . It is composed of a ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms ...

Wiktionary Word definitions in Wiktionary
n. (context vitamin English) A sulfur-containing member of the vitamin B complex found in liver, egg yolk, milk and yeast, essential to the activity of multiple enzyme systems.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
vitamin of the B group (also sometimes called vitamin H ) essential for the growth of yeast, 1936, from German Biotin (1936), from Greek biotos "life" (see bio- ) + chemical suffix -in (2).

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
biotin \bi"o*tin\ n. a B vitamin ( C10H16N2O3S ) that aids in body growth; -- called also vitamin H and coenzyme R . It functions as a coenzyme in many carboxylation reactions. Note: Biotin binds tightly to the substance avidin, found in raw egg-whites. ...