☆ a synthetic, microscopic globule consisting of layers of lipids encapsulating certain substances (as enzymes or drugs): used to introduce these substances into a cell or specified tissue
Origin:
lipo- + -some
See liposome in American Heritage Dictionary 4
noun
An artificial microscopic vesicle consisting of an aqueous core enclosed in one or more phospholipid layers, used to convey vaccines, drugs, enzymes, or other substances to target cells or organs.