Main Entry: epi·some

Pronunciation: \ˈe-pə-ˌsōm, -ˌzōm\

Function: noun

Date: circa 1931

: a genetic determinant (as the DNA of some bacteriophages) that can replicate autonomously in bacterial cytoplasm or as an integral part of the chromosomes

— epi·som·al \ˌe-pə-ˈsō-məl, -ˈzō-\ adjective

— epi·som·al·ly \-mə-lē\ adverb