disproportionation

noun

dis·​pro·​por·​tion·​ation ˌdis-prə-ˌpȯr-shə-ˈnā-shən 

: the transformation of a substance into two or more dissimilar substances usually by simultaneous oxidation and reduction

disproportionate

ˌdis-prə-ˈpȯr-shə-ˌnāt 

intransitive verb

Word History

Etymology

disproportion entry 2 + -ation

First Known Use

circa 1929, in the meaning defined above