flatterer; smooth talker; crafty person
A person who uses insincere praise or cunning speech to manipulate others. This word is rare and somewhat literary; in everyday conversation, terms like お世辞屋 or 口のうまい人 are more common.
He is a flatterer, skilled at ingratiating himself with his boss.
That politician was criticized as a smooth-talking manipulator.
The kanji 佞 means 'flattery' or 'craftiness', and 人 means 'person'. The exact historical derivation is uncertain, but the compound directly conveys the meaning of a deceitful or flattering individual.