what is the translation for 或啁之曰 ? A random phrase from Lun-Heng begins with 或啁之曰, 

as far as I understand its parts mean:


或 someone
啁 to chirp, to twitter
之 objectpronoun "it,him,her" as in "I like him, I talk about it"
曰 to say (stands right before a verbatim quotation)**


rendered into one sentence: 

someone twittered it saying: "..."

I do not understand how 啁 to twitter fits into it, because if one twitters one makes sounds of a bird and does not speak to convey a contend.
Here 啁 is a phonetic loan for 嘲, 'to mock', as in 嘲笑, so the phrase 或啁之曰could be translated "Someone mocked him, saying..." Using one character for another because they are pronounced similarly is common in older works.  You could compare it to the situation in earlier English works where the same word is often spelled different ways, even in the same sentence.  

I doubt there is any regular semantic relationship between 啁 in the sense of 嘲, and 啁 in the sense of 'noisy'. As the comment by nee.wong notes, although phonetically similar, they are still pronounced differently. In fact, 啁 meaning 'noisy' usually occurs only in onomatopoeic phrases such as 啁啾 zhoujiu or 啁哳 zhouzha.