The phrase "sell a gold brick to" is used to describe someone who is easily misled or deceived. There are numerous synonyms that can be used to convey the same meaning. Some commonly used synonyms are 'swindle', 'hoodwink', 'bamboozle', 'defraud' and 'cheat'. Other synonyms include 'dupe', 'trick', 'fool', 'deceive', 'mislead' and 'beguile'. It's important for individuals to be aware of such synonyms as they can help them identify situations where they may be at risk of being deceived. Being aware and informed can help people protect themselves from such fraudulent activities.