WordReference Random House Unabridged Dictionary of American English © 2026
ep•i•some
(ep′ə sōm′),USA pronunciation n. [Genetics.]
ep′i•so′mal, adj.
ep′i•so′mal•ly, adv.
- Geneticsbacterial DNA that is extrachromosomal and that may replicate autonomously as a plasmid or become incorporated into the chromosome and replicate with it.
- epi- + -some3 1930–35
ep′i•so′mal•ly, adv.