protoactinium

[proh-toh-ak-tin-ee-uh m] /ˌproʊ toʊ ækˈtɪn i əm/
noun, Chemistry
British Dictionary definitions for protoactinium

protoactinium

/ˌprəʊtəʊækˈtɪnɪəm/
noun
1.
the former name of protactinium