The word 呆子 is formed by directly combining two characters: the first, 呆, depicts a wooden, dull, or foolish state, often visualized as a mouth (口) under a tree (木), suggesting someone so simple they are like a motionless log; the second, 子, is a common suffix attached to nouns to denote a person. When fused, the literal "dull person" becomes a single, colloquial unit meaning "fool" or "idiot", where the suffix completes the transformation of an adjective-like quality into a concrete label for a human type.