汉：来源于希腊语，意为"through,across,between,intensive"。在元音字母前，字母A部落，dia变为di。
英：before vowels, di-, word-forming element meaning "through, thoroughly, entirely," from Greek dia-, from dia "through, throughout," probably from the root of duo "two" (see two) with a base sense of "twice."
1.diabolical
adj.of or like a clevil;very cruel or wicked恶魔，恶魔一样的；残忍的，十恶不赦的 *dia (=across),bol (=throw)
例句：We can no longer put up with Frank's diabolical behavior.我们再无法容忍弗兰克的黑恶行径。
2.diadem
n.crown 王冠 *dia (=through),dem (=band)
例句：Also found in the tomb was a diadem believed to have belonged to the queen.坟墓里又挖出一顶王冠，据推定，这顶是女王的王冠。
3.diagnosis
n.determining the nature of a disease,etc.from observations of symptoms 诊断测试的结果是发动机的一个活塞不工作了。
4.diagnostic
adj.of diagnostic 诊断的 *dis (=through),gno (=know)
例句：Dector Smith wants to conduct at diagnostic examination of your liver.史密斯医生想对您的肝脏作一个珍断性的检查。
5.diagonal
n./adj. (straight line) going across a straight-sided figure 对角线（的）*dia (=across),gon (=angle)
例句：That red diagonal line on the map indecates the route of Highway 42.地图上的红色对角线就是42号公路线。
6.diagram
n.drawing ,design or plan to explain or illustate something. 图形，图表，图解 *dia (=across) ,gram(=write)
例句：Andy supplemented his presentation with charts,grphs and diagrams.安迪又为他的发言补充了一些曲线，示意图和图表。
7.diatect
n. form of a language used in a part of a country or by a class of people 方言，地方土语*dia (=through,between),lect(=choose,talk)
例句：Over 20 different dialect are spoken here,but Hakkian is the unofficial language of the province.这儿有20多种方言，但是客家话并不是该省的官方语言。
8.dialogue
n.conversation or talk 对话 *da(=between),log(=speech)
例句：As a first step,the Americans hope to engage the warring parties in a dialogue on possible peace initiatives.首先，美国人希望争吵不休的党派能参加对话，以主动推动可能实现的和平。
9.diameter
n.measurement across any geometrical figure or body;length of a straight line drawn from side through the center 直径 *dia(=across),meter(=measure)
例句：Place the plant in pot with a diameter of no less than 16 centimeters.请愿书把那株植物种在直径不小于16cm的花盆里。
10.diaphragm
n.internal wall of muscle between the chest and the abdomen;arrangement of thin plates that control the inlet of light;vibrating disc or cone in a telephone receiver ,etc.横膈膜；光圈；震动膜 *dia(through),phragm(=fence)
例句：Professional singers use the air from their diaphragm to push out each note.专业的歌唱家利用来源于横囊肿膜的空气唱出每一个音符。
11.diocese
n.the district under a bishop's jurisdiction 主教 *di<dia(=through),oce<eco(=house)
例句：your children may attend any of the schools run by the diocese free of charge.您的孩子可以免费进入主教辖区内的任何一所学校。