插图
chā tú · HSK 7
illustration
🖼️ 插图 = 插 insert + 图 diagram = a diagram inserted into a book
插 means to insert or stick in; 图 means picture or diagram. An illustration is a picture inserted into the text of a book or article.
插 — hand radical 扌 + 臿 (pestle in mortar)
Originally a semantic-phonetic compound: 扌 (hand) gives the meaning of a manual action, while 臿 depicts a pestle being thrust into a mortar, supplying both sound and the sense of pushing in. The combined character came to mean 'to insert, stick in, or plant,' extending from the image of a hand driving something downward.
图 — enclosure 囗 + 冬 (simplified from 啚)
Originally written 圖, showing an enclosure 囗 around 啚, a depiction of a granary or rural settlement on a map. The whole character meant a map or chart of demarcated territory. Meaning later broadened to picture, diagram, or to plan/scheme.