any of a group of organelles in some cells of mammals, the leaves of plants, etc., containing enzymes that produce and then decompose hydrogen peroxide: thought to be involved in cellular metabolism
See peroxisome in American Heritage Dictionary 4
(pə-rŏkˈsĭ-sōmˌ)
noun
A cell organelle containing enzymes, such as catalase and oxidase, that catalyze the production and breakdown of hydrogen peroxide.