American English

Definition of protactinium noun from the Oxford Advanced American Dictionary

 

protactinium

 noun
noun
NAmE//ˌproʊtækˈtɪniəm//
 
[uncountable] (symbol Pa)
 
jump to other results
a chemical element. Protactinium is a radioactive metal found naturally when uranium decays.
See the Oxford Advanced Learner's Dictionary entry: protactinium