noun
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.
彼の知識は字引学問に過ぎない。
His knowledge is nothing more than superficial book learning.
字引学問では実社会で役に立たない。
Mere book learning won't help you in the real world.
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.