diagram (n.)youdaoicibaDictYouDict[diagram 词源字典]
1610s, from French diagramme, from Latin diagramma, from Greek diagramma "geometric figure, that which is marked out by lines," from diagraphein "mark out by lines, delineate," from dia- "across, out" (see dia-) + graphein "write, mark, draw" (see -graphy). The verb is 1840, from the noun.[diagram etymology, diagram origin, 英语词源]