ra·di·o·i·so·tope 
(rā′dē-ō-īsə-tōp′)
(rā′dē-ō-īsə-tōp′)n.
A naturally or artificially produced radioactive isotope of an element.
- precisian
- precisianism
- precision
- precisionism
- precisionist
- preclinical
- preclude
- preclusion
- preclusive
- preclusively
- precocial
- precocious
- precociously
- precociousness
- precocity
- precognition
- precognitive
- precolonial
- pre-colonial
- pre-Columbian
- precolumbian
- preconceive
- preconception
- preconcert
- precondition