superficial learning; book learning; knowing many words without deep understanding
Often used critically for someone who knows many words or facts but lacks real understanding or practical wisdom. The term 字引 (dictionary) + 学問 (learning) suggests learning that is like a dictionary: full of entries but shallow.
His knowledge is nothing more than superficial book learning.
Mere book learning won't help you in the real world.
机上の空論 refers to an impractical theory or armchair argument, while 字引学問 focuses on shallow, dictionary-like knowledge without depth.
生兵法 means a little knowledge that can be dangerous; 字引学問 is more about superficial breadth rather than dangerous half-knowledge.
Compound of 字引 (dictionary) and 学問 (learning, scholarship). The exact historical origin is uncertain, but the term evokes the image of learning that is as shallow as a dictionary entry.