n.
Pronunciation: ī - ' ō -n ē - ə m
Function: noun
Etymology: ion; from its ionizing action
Date: 1907
: a natural radioactive isotope of thorium having a mass number of 230
IONIUM
Meaning of IONIUM in English
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012