妄言 literally combines 妄 (wàng), meaning 'reckless', 'unfounded', or 'arrogant', and 言 (yán), meaning 'speech' or 'words'. Together, it refers to statements made without basis, evidence, or proper authority — often implying arrogance, carelessness, or deliberate falsehood. It carries a strong negative connotation and suggests the speaker is overstepping bounds of reason or propriety.

This term is commonly used in formal or literary contexts — such as news reports, political commentary, or classical-style writing — to criticize unfounded claims, rumors, or irresponsible public statements. While it can describe spoken words, it’s more frequently applied to written or public utterances with social or moral weight. It is not used for casual mistakes or innocent misunderstandings, but rather for speech that reflects serious lack of judgment or integrity.