tin sái cổ

== Vietnamese == === Etymology === (This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.) === Pronunciation === (Hà Nội) IPA(key): [tin˧˧ saːj˧˦ ko˧˩] (Huế) IPA(key): [tin˧˧ ʂaːj˨˩˦ kow˧˨] ~ [tin˧˧ saːj˨˩˦ kow˧˨] (Saigon) IPA(key): [tɨn˧˧ ʂaːj˦˥ kow˨˩˦] ~ [tɨn˧˧ saːj˦˥ kow˨˩˦] === Verb === tin sái cổ (idiomatic) to take something (usually a fraudulent claim) as a matter of fact without further inspection; to be too credulous