Main Entry: glu·ca·gon

Pronunciation: \ˈglü-kə-ˌgän\

Function: noun

Etymology: gluc- + -agon (perhaps from Greek agōn, present participle of agein to lead, drive) — more at agent

Date: 1923

: a protein hormone that is produced especially by the islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of glycogen breakdown in the liver