1. a passage or transfer, as of a disease from one individual to another, or of neural impulses from one neuron to another. 2. the communication of inheritable qualities from parent to offspring. horizontal transmission the spread of an infectious agent from one individual to another, usually through contact with bodily excretions or fluids, such as sputum or blood, that contain the agent. vertical transmission transmission from one generation to another. The term is restricted by some to genetic transmission and extended by others to include also transmission of infection from one generation to the next, as by milk or through the placenta.
1. Synonym(s): transfer