The story
From plasma + -id, coined by American molecular biologist Joshua Lederberg in 1952.
Etymology from Wiktionary, CC BY-SA 4.0.
plasmid
Today it means: A loop of double-stranded DNA that is separate from — and replicates independently of — the chromosomes; such loops are most commonly found in bacteria, but they are also sometimes found in archaeans and eukaryotic cells, and they are used in genetic engineering as a vector for gene transfer. Full definition →