英语中的数字前缀主要有两个来源
英语中的数字前缀主要有两个来源，楼上给出的是希腊源的数字字头，此外很常见的还有拉丁源的数字字头。虽然每个数字都有两种表示，但由于语源学的原因，这两种来源的数字前缀往往出现在不同类型的单词中。 拉丁数字前缀如下：
拉丁源的前缀与不同的后缀结合多用于: 数学基数 decimal 关系形容词 quaternary 音乐家组合 quartet 表示倍数的词 triple 表示两个事件之间相隔的年份 quinquennial 表示有关方面的数目 bilateral 表示大数、幂的词 trillion 叶数或花或叶的瓣数 trifoliate 化学键 trivalent
希腊数字前缀如下：
1 mono
2 di/dy
3 tri
4 tetra
5 penta
6 hex
7 hept
8 oct
9 ennea 10 dec(a) 11hendec(a) 12 dodec(a) 13triskaideca/trideca 14tetrakaideca/tetradeca 15 pendeca 16 hexadeca 17heptadeca 18 octodeca 19 enneadeca 20 icos(a) 21 henicosa 22doicosa 23triicosa 24 tetraicosa 25 pentaicosa 26 hexaicosa 27 heptaicosa 28 octaicosa
希腊源的前缀与不同的后缀结合多用于: 平面图形的边数 pentagon 立体图形的面数
dodecahedron 某形状或线条的角数 triangle 统治者的成员个数 monarchy 诗歌的步格数 heptameter 一个集合中的元素数 triad 田径比赛的项目数 pentathlon
英语词根词源数字篇 uni- 表示"一","单一的" bi- 表示"二","二的" ambi- 表示"二","二者" tri- 表示"三","三倍" quadri- 表示"四","四倍"
============================= One Uni-
1.unicorn / / n.独角兽mythical animal resembling a horse with a single straight horn projecting form its forehead uni- (one)+corn (horn)
2.uniform/ /adj.相同的、无变化的not changing in form or character ; unvarying n.制服distinctive clothing worn by all members of an organization uni- (one)+form
e.g. : The house was kept at a uniform temperature.
3.unique/ /adj.唯一的、独特的being the only one ;have no like or equal e.g. : Her designs are quite unique in today’s fashion scene.
1 uni
2 bi/duo
3 tri 4quadri/quart 5quinque/quint 6 sex(t)/se 7 sept 8 oct 9 nonus/novem 10 dec(a)/de 11 dec/unde 12 duodec/duode 13 tredec/tridec 1
4 quatuodec 1
5 quindec(c) 1
6 sede(c) 1
7 septende(c) 1
8 decennoct 1
9 decennov 20 vige/vice 21 unviginti 22 duoviginti 23 treviginti 24quattuorviginti 25 quinviginti 26 sexviginti 27 septenviginti 28 octoviginti
4.unanimous/ /adj.意见一致的；一致同意的all agreeing on a decision or an opinion
uni-(one)+anim (mind)+-ous(形容词词尾)
e.g. :He was elected by unanimous vote.
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Two, double
Bi-
1.bicameral/ /adj.having two legislative chambers（议会）两院制的（如英国的上议院和下议院）
bi-(two)+camer (chamber)+-al(形容词尾)
e.g. a bicameral system of government两院制政体
2．biweekly/ /adj.adv.两周一次的（地）;隔周的（地）
bi-(two)+week+ly(副词词尾)
e.g. We hold our regular meeting biweekly.
3.bilingual/ /adj.会两种语言的able to speak, express ,write two languages equal well
bi-(two)+lingua(language)+-al(形容词尾)
e.g. He is bilingual in French and Spanish.
Di-
1.dilemma/ /n.进退两难的窘境situation in which one has to choose between two undesirable thing or courses of action
di-(double)+lemma(assumption)
e.g. The dilemma the doctor faced was whether he should tell the patient the truth. [idm] on the horns of a dilemma 左右为难
2．diphthong/ /n.双元音（如au）union of two vowel sounds or vowel letters
di-(double)+phthong(sound)
3.diploma/ /n.文凭；毕业证书（对折的纸）certificate awarded for passing an examination di-(double)+ploma(folded)
e.g. After graduation, he got a diploma in architecture.
Duo- [变化型]do-, dou-, du-
1.duologue/ /n.对话；（戏剧中的）对白conversation between two people
dou-(two)+logue(speech)
2.duplicate/ /adj.完全相同的，复制的identical;twoflod,double
du-(two)+plic(to fold)+-ate(形容词词尾)
e.g. This research merely duplicates work already done elsewhere.
3.duel/ /n.v.决斗formal fight between two men
e.g. Because of the beautiful girl, Tom challenged Jimmy to duel.
Twi-
1.twice/ /adj.二倍；二回；二度double; two times
e.g. He has twice lied to us.
2.twilight/ /n.（日出前的）微明；黄昏（明暗两者之间的光）faint light after sunset or before sunrise
e.g. Twilight is a dangerous time for drivers.
3.twist/ /v.卷缠；曲解（两个缠在一起）
e.g. I twisted the bandage round her knee.
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Three
Tri-
1.tribe/ /n.种族；一群人；一类人racial group united by language, custom, religion large number of people; set or class people
tri-(three)+be =拉丁文bus (family)
e.g. I hate the whole tribe of politicians.
[词源] 古时位于罗马的三个种族the Ramnes, Tities, Luceres中任何一省均称tribe，此种称法沿用至今。
2.trilateral/ /adj.有三边的n.三边形involving three sides, groups, countries
tri-(three)+later(side)+- al(形容词词尾)
e.g. After overheated discussion, they reached a trilateral agreement.
3.triple/ /adj.三倍的，三部的n.三倍v.使成三倍having three parts; three times
tri-(three)+ple(to fold)
e.g. He tripled his income in three years.
4.trival/ /adj.不重要的；琐碎的that has little importance
tri-(three)+via(way)+- al(形容词词尾)
e.g. You should pay great attention to even a trival mistake.
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Four
Quadri-
1.quadruped/ /n.四足兽four-footed animal
quadru-(fourfold)+ped(foot)
2.quadriplegia/ /n.四肢麻痹
quadri-(four)+pleg (paralysis麻痹)+-ia (condition)
3.quadrennial/ /adj.持续四年的；每四年一次的lasting for four years; happening every fourth year
quadr-(four)+enn(year)+-ial (形容词词尾)
Tetra-
1.tetragon/ /n.四角形；方形建筑
tetra-(four)+gon(angle)
2.tetrahedron/ /n.四面体
tetra-(four)+hedr(side)+-on(名词词尾)
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Five
Penta-
1.pentagon/ /n.五角形geometric figure with five sides and angles
penta-(five)+gon(angle)
[注]五角大楼（美国国防部办公处）（位于福吉尼亚州的阿灵顿）the five-sided building department of Defence and the US armed forces
2.pentarchy/ /n.五头政治；五国联盟
penta-(five)+archy (rule)
3.pente-cost/ /n.（犹太人的）五旬节（庆祝收获的节日）Jewish harvest festival that takes
place fifty days after the second day of Passover
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Six
Sex-
1.sexagenarian/ /n.60-69岁之间的人(person who is) of any age from 60-69
2.sexpartite/ /adj.分成六部分的
sex-(six)+ part + -ite (形容词词尾)
3.sexcentenary/ /n. adj.六百周年纪念（的）
sex-(six) + cent(hundred)+ en(year)+-ary（形容词兼名词词尾）
Hex (a)-
1.hexagon/ /n.六角形geometric figure with six sides and angles
hexa- (six) + gon(angle)
2.hexameter/ /n.有六个韵部的诗行line of verse with six metrical foot
hexa- (six)+ meter( to measure )
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Seven
Sept-
1.septet/ /n.七重奏（曲）；七重唱（曲）piece of music written for a group of seven instruments or singers
2.septennial/ /adj.连续七年的；七年一次的
sept- (seven)+enn(year)+-ial (形容词词尾)
3.september/ /n.九月the ninth month of the year, next after August but the seventh month of the Roman year
e.g. September showers, short periods of rain alternating with hot weather.
[注]恺撒之前的罗马历是以三月（March）为始，共有十个月。当时的七月称为。后来加上了一月（January）、二月（February）而成十二个月，但其余各月的名称并没有改变，只是往后顺延两个月，乃称九月为September, 其余依次类推：September（七月—九月），November（九月—十一月）。
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Eight
Octa-, Octo-
1.octogenarian/ /n.80-89岁之间的老人persons between 80 and 89 of age
2.octagon/ /n.八角形
octa- (eight)+gon(angle)
3.octopus/ /n.章鱼；强有力且能为害的组织sea-animal with a soft body and eight long arms with suckers on them
octo- (eight)+pus(foot)
e.g. Have you ever tasted octopus?
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Ten
Deca-
1.decade/ /n.十年；由十所构成的一组period of ten years
e.g. the first decade of 20 century
2．decameron/ /n.十日谈
deca- (ten)+meron(day)
[注]意大利Boccaccio所著，包括100个故事3.decapod/ /n.十脚类动物（如虾等）
dec-(ten)+pod(foot)
4.decimal/ /n. Adj.十进制（的）；小数（的）decima(tithe十分之一)+ -al (形容词词尾) e.g. decimal point 小数点