[en-dawr-fin] 
| any of a group of peptides occurring in the brain and other tissues of vertebrates, and resembling opiates, that react with the brain's opiate receptors to raise the pain threshold. |
| en·dor·phin (ěn-dôr'fĭn) n. Any of a group of peptide hormones that bind to opiate receptors and are found mainly in the brain. Endorphins reduce the sensation of pain and affect emotions. [endo(genous) + (mo)rphin(e).] |
Substances produced by the brain that have painkilling and tranquillizing effects on the body. Endorphins are thought to be similar to morphine and are usually released by the brain during times of extreme body stress. The release of endorphins may explain why trauma victims sometimes cannot feel the pain associated with their injuries.
endorphin en·dor·phin (ěn-dôr'fĭn)
n.
Any of a group of peptide hormones that bind to opiate receptors and are found mainly in the brain. Endorphins reduce the sensation of pain and affect emotions.
fɪn