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protoactinium

American  
[proh-toh-ak-tin-ee-uhm] / ˌproʊ toʊ ækˈtɪn i əm /

noun

Chemistry.

  1. protactinium.

protoactinium British  
/ ˌprəʊtəʊækˈtɪnɪəm /

noun

  1. the former name of protactinium

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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.