Diachronic is a 10 letter English word. It's valid Words with friends word worth 20 points.
You can make 461 anagrams from letters in diachronic (accdhiinor).
1925-30; French diachronique (term introduced by F. de Saussure); see dia-, chronic
The two creations,—the extinct and the extant,—or rather the prochronic and the diachronic—here unite.
Now, again I repeat, there is no imaginable difference to sense between the prochronic and the diachronic development.