noun
1. : a hypothetical computing machine that can reproduce itself
2. : an element in a computer simulation composed of semiautonomous interacting elements ; specifically : any of such elements that are visualized on a computer screen as square or hexagonal cells comprising an array, grid, or lattice, that are controlled by similar but separate software routines or hardware devices, that can exist in a number of states, that are influenced by the states of their neighbors, and that are used to simulate diverse complex systems (as neuronal activity in a brain or traffic flow patterns)