|dīə|kränik adjective
or dia·chro·nis·tic |dīəkrə|nistik, -(ˌ)krä|n-; (|)dī|akrə|n- ; or di·ach·ro·nous (ˈ)dī|akrənəs
Etymology: diachronic, International Scientific Vocabulary dia- + chronic; originally formed as French diachronique; diachronistic from dia- + -chronistic (as in synchronistic ); diachronous from dia- + -chronous
: considering or embracing phenomena (as the sounds of a language) as they occur, change, or develop over a period of time — contrasted with synchronic
diachronic descriptions of a language are properly built up by a comparison of synchronic descriptions of the same language at different historical periods — D.W.Reed
• dia·chron·i·cal·ly |dīə|kränə̇k(ə)lē adverb
• di·ach·ro·nous·ly (ˈ)dī|akrənəslē adverb