coextinction in English dictionary coextinction Meanings and definitions of "coextinction" (biology) The simultaneous extinction of two or more species (especially when one is dependent on the other) noun (biology) The simultaneous extinction of two or more species (especially when one is dependent on the other) more Grammar and declension of coextinction coextinction ( plural coextinctions) more Sample sentences with "coextinction" Declension Stem Try again Authors