noun
superficial knowledge; half-baked understanding
Describes knowledge or understanding that is shallow, incomplete, or not properly digested. Often used critically of someone who has only a surface-level grasp of a subject.
彼の説明は生飲み込みで、深い理解が感じられない。
His explanation is superficial and lacks deep understanding.
生飲み込みの知識で議論しても説得力がない。
Arguing with half-baked knowledge isn't persuasive.
浅い is a general adjective for 'shallow' and can be used for physical depth or superficiality, whereas 生飲み込み is a noun limited to intellectual shallowness.
Compound of 生 (nama, 'raw, unprocessed') and 飲み込み (nomikomi, 'swallowing, understanding'). The image is of swallowing something raw without properly digesting it, hence 'superficial understanding'.