- Main Entry:
- ker·a·tin

- Pronunciation:
-
\ˈker-ə-tən\
- Function:
- noun
- Etymology:
- International Scientific Vocabulary
- Date:
- circa 1849
: any of various sulfur-containing fibrous proteins that form the chemical basis of horny epidermal tissues (as hair and nails)
—
ke·ra·ti·nous
\kə-ˈra-tə-nəs\
adjective