shallow, glib, and obsequious person
A yojijukugo describing someone who is superficially clever and smooth-talking but lacks depth, often flattering others for personal gain.
He is a shallow, glib flatterer who always says nothing but flattery in front of his boss.
That politician is nothing more than a shallow, smooth-talking sycophant with no real policies.
軽薄 is an adjective meaning 'shallow' or 'frivolous', while 軽薄才子 is a noun referring to a person who embodies that shallowness combined with glibness and obsequiousness.
才子 means 'talented person' or 'wit', but in 軽薄才子 it takes on a negative connotation of superficial cleverness used for flattery.
A yojijukugo combining 軽薄 (frivolous, shallow) and 才子 (talented person, wit). The exact origin is uncertain, but it follows a common pattern of four-character compounds that describe a person's character.