exegesis, critical analysis of classical texts
詁 centers on scholarly interpretation of ancient texts: the careful analysis and explanation of classical writings to uncover their meaning.
詁 combines 言 (speech, words) with 古 (old, ancient), suggesting the explanation of old words or classical texts.
Words 言 about the ancient past 古: a scholar speaking to clarify old texts. 詁 is the act of interpreting classical writings.
For コ, imagine a scholar saying 'co-' as the start of 'commentary' while explaining an ancient text: co -> コ.