What is another word for radioactive?

There isn't one single perfect synonym for "radioactive," as it has a very specific meaning. However, depending on the context, you could use some of these alternatives:

General alternatives:

* Radioactive

* Emitting radiation

* Radiating

* Isotopic (if referring to specific radioactive isotopes)

Alternatives focusing on the effect:

* Dangerous

* Harmful

* Toxic

* Contaminated (if referring to a substance or area)

Alternatives focusing on the process:

* Decaying (if referring to radioactive decay)

* Transforming (if referring to nuclear transformations)

* Emitting particles

The best alternative will depend on the specific context and the intended meaning.