Chinese character 譠

In 譠謾, it points to deceptive speech.

The earliest known attestation is in the Western Han Fangyan, a text that records regional vocabulary. Its phrase 譠謾 labels deceptive or boastful speech in regions south of Chu and Ying and around Dongyang.

That makes the surrounding passage essential: 譠 is documented in a regional expression, not as an everyday standalone word.

Why is 譠 linked with 詚 and 誕?

Their connection is historical, not just visual.

A study of ancient Chinese writing links 譠 to 詚, found in Warring States Chu bamboo slips, and to 誕 through sound and meaning. It treats 詚 and 譠 as possible earlier and later, or variant, writings; their exact chronology is unsettled.

After Fangyan, later dictionary glosses add slow or relaxed; 冷譠 is glossed as not caring.

Someone sent me 譠—what should I do?

A bare send does not identify the intended sense.

Its documented readings come from historical phrases and dictionary glosses. Ask for the sentence or source; that context can tell you which sense the sender means.