self-as·sem·bly • n. 1. Biol. the spontaneous formation of a ribosome, virus, or other body in a medium containing the appropriate components. ∎ a manufacturing process in which atoms, molecules, and components arrange themselves into ordered, functioning entities with no active human involvement2. Brit. the construction of an object, esp. a piece of furniture, from materials sold in kit form: [as adj.] self-assembly furniture. DERIVATIVES: self-as·sem·ble v.