「drug」和「毒」是同源词吗?
不是。但相比很多用现代汉语发音来研究中西同源的学者而言，题主水平比他们高多了。查词源词典得知，英字 drug 来源于古法文 droge（供给）。 droge词源不明，但推测来自于中古荷语或低地德语 droge-vate或 droge waere，跟乾货桶、乾貨、乾草藥有关。late 14c., drogge(early 14c. in Anglo-French), "any substance used in the composition orpreparation of medicines," from Old French droge "supply, stock, provision"(14c.), which is of unknown origin. Perhaps it is from Middle Dutch or MiddleLow German droge-vate "dry barrels," or droge waere, literally "dry wares"(but specifically drugs and spices), with first element mistaken as indicatingthe contents, or because medicines mostly consisted of driedherbs.而汉字「毒」，很早就有毒害的意思。《说文段氏注》：厚也。毒厚疊韵。三部、四部同入也。毒兼善惡之辭。猶祥兼吉凶，臭兼香臭也。易曰：聖人以此毒天下而民從之。列子書曰：亭之毒之。皆謂厚民也。毒與竺篤同音通用。微子篇：天毒降災。史記作天篤。害人之艸。往往而生。从屮。字義訓厚矣。字形何以从屮，葢製字本意。因害人之艸，往往而生，往往猶歷歷也。其生蕃多則其害尢厚，故字从屮，引伸爲凡厚之義。从毐。（改作「毐聲」。）毐在一部，毒在三部，合韵至近也。