Tonian

/ˈtoʊ.ni.ən/

UK: /ˈtəʊ.ni.ən/

TOƱ · ni · ən (3 syllables)

English Adj

Definition

Of a geologic period within the Neoproterozoic era from about 1000 to 850 million years ago.

Etymology

From Ancient Greek τόνος (tónos, “stretch”).