stereochemistry (stÄr'Ä-Å-kÄm'Ä­-strÄ) The branch of chemistry that deals with the spatial arrangements of atoms in molecules and with the chemical and physical effects of these arrangements.
ECU. Short for Electronic Control Unit, the ECU is a name given to a device that controls one or more electrical systems in a vehicle. It operates much like the BIOS does in a computer.
ECU. An electronic device that remotely controls home climate (e.g., heating, air conditioning), security (e.g., lighting, door locks, drapes), and communication devices (telephone, television). ECUs are often, but not exclusively, used by persons with functional limitations.