Humoralism: An ancient theory holding that health came from balance between the bodily liquids termed humors. Disease was thought to arise when imbalance occurred between the humors. The humors were phlegm (water), blood, gall (black bile, thought to be secreted by the kidneys and spleen), and choler (yellow bile secreted by the liver). The humoral theory was devised well before Hippocrates, and it was not definitively demolished until 1858. The word humor lives on as a medical term for liquid or semiliquid substances in the body and as a euphemism for mood (such as being 'in good humor'). Also known as humorism.