1. One that reacts
2. A device (as a coil, winding, or conductor of small resistance) used to introduce reactance into an alternating-current circuit
3. A vat for an industrial chemical reaction; a device for the controlled release of nuclear energy (as for producing heat)
4. An electrical circuit element used to introduce reactance into the circuit.
Nuklearno postrojenje, srce "nuklearke", nuklearni reaktor (lat.)