Shallow; superficial—lacking depth in thought or knowledge, often implying shallowness or triviality.
彼の議論は浅薄で説得力に欠ける。
His argument is shallow and lacks persuasive power.
浅薄な知識で判断してはいけない。
You shouldn't make judgments based on superficial knowledge.
浅薄に結論を出すと後で後悔することになる。
If you draw a shallow conclusion, you'll regret it later.