前缀pre-词源、用法和例词
词源：
前缀pre-与前缀post- 是一对相反的词缀，它来源拉丁介副词prae,原意为before,beforehand 或in front，即表示时间或空间上的“前”。pre- 原是个有副词含义的原生词，出现于拉丁语源的原生词中。但自15世纪以来，它成为一个活性的派生词缀，能与许多单词缀合，起介词性或修辞性的作用。当介词性的pre- 与名词缀合时，可能改变词基单词的词性。当派生前缀pre-出现在以e开头的单词或大写字母时，要加连接字符。此外，应注意原生前缀pre-中的e读短音/I/,而派生前缀pre- 中的e念长音/i:/。
英语词源：
word-forming element meaning "before," from Old French pre- and Medieval Latin pre-, both from Latin prae (adverb and preposition) "before in time or place," from PIE *peri- (cognates: Oscan prai, Umbrian pre, Sanskrit pare "thereupon," Greek parai "at," Gaulish are- "at, before," Lithuanian pre "at," Old Church Slavonic pri "at," Gothic faura, Old English fore "before"), extended form of root *per- (1)"beyond" (see per).
The Latin word was active in forming verbs. Also see prae-. Sometimes in Middle English muddled with words in pro- or per-.
前缀PRE来源于拉丁语，意为“before”，下面重点看一下PRE的主要意思"before”。
1.先前，前，早一点，以前
predilection, preview, pretext
2.前面，提前，在前面的，向前,预先
prefatory, preamble, precipice
此外，前缀pre-还有一些同义前缀，它们也具有“事先，以前”的意思；还有一些反义词缀，它们具有“后面，以后”的意思。
1．同义前缀:ante,fore
2.反义词缀：post,retro,re
例词：
1.precaution [pre（=before）+cau( =take care)事先小心，注意]
n. care taken in advance to avoid a risk 小心，警惕，预防
precautionary 预防的，警惕的
举例： As a precaution, please fasten your seat belt before starting the car.
作为一种预防措施，请在发动汽车之前系好安全带。
2.prevail [pre( =before) +vail( =strength,worth)力量领先的]
v.gain victory over; be widespread; be generally seen, done, etc.; be effective;
persuade 占优势，战胜；普及，盛行；有效；说服
prevailing 占优势的；普及的，流行的；有效的；占支配地位的 prevalent 普及的，流行的 prevalence 普及，流行
举例： Although the team was down in the 3rd quarter, in the end they prevalled.
虽然那个队在第三局处于劣努，不过最终他们还是赢了。
3.predecessor [pre( =before) +de( =down) +cess( =go)领先往下走]
n. former holder of any office or position; ancestor; thing to which another has succeeded 前任；祖先；被代替的原有事物
举例： The new Miss America was crowned by her predecessor.
前任美国小姐给新当选的美国小姐戴上了桂冠。
4.premature [(pre( =before) +mat( =ripe)早一点熟的]
adj. happening or coming before the proper time; too early, untimely 时机尚早的；太早的．不到期的；早产的
举例： It would be premature to fire her; she's still learning her job.
现在解雇她为时尚早，她还在熟悉工作。
5.prescibe [(pre( =before) +scrib( =write)事先写]
v. set down as a direction or rule; order as a medical treatment 规定，命令；开处方
prescription 处方；命令，指示，规定，法规 prescript 命令，规定，法令，法律
prescriptive 规定的，规范的；约定俗成的
举例： The doctor prescribed some tranquilizers and a few days of rest.
医生开了一些镇静剂，让休息几天。
6.presume [(pre(=before)+sum(=take)事先抓住、思考]
v. make supposition; venture; make a wrong use of 推断；擅自（做）,冒昧（做）
presumption 推断；放肆；专横 presumptuous 放肆的；专横的；傲慢的
presumable 可以推断的 presuming 放肆的，冒昧的 presumptive 推断的
presumably 据推测；可能
举例：I prosume you'll beflying, not driving, right?
我猜你会坐飞机，而不是自己开车，对吧？
7.preview [(pre(=before)+view( =look)事先看]
n. view of a film,play,etc. betore it is shown to the general public 电影等的试映，预演
vt. have a preview of 试映，预演
举例：l first saw Raiders of the Lost Ark at a sneak preview——and love it!
第一次看<夺宝奇兵>是在试映会土，我很喜欢！
8.preclude [(pre (=before) +clud( =shut)事先关上，关押起来]
adj. prevent; make impossible in advance 阻止，妨碍；排除；防止
preclusion n. 排除；妨碍；防止 preclusive adj. 排除的；妨碍的；防止的
举例： Some medical conditions preclude getting facial cosmetic surgery.
有些医疗条件会妨碍脸部整形手术。
9.predominant [(pre( =before) +domin（=master）提前征服、熟练、精通]
adj. having more power or influence than others; prevailing; conspicuous 突出的，支配的；主要的，占优势的；显著的，显眼的
predominate 支配；占优势
predominance 支配；优势；显著 predominantly 支配地；显著地
举例： The predominant color in her decorating scheme is taupe.
她的装饰方案以褐灰色为主色。
10.preamble [(pre( =before) +ambl<ambul( =walk, go)捉前走、去]
n. introduction or preliminary statement, especially to a formal statement （正式文书的）序言，前言
举例： My editor asked me to write a short preamble to my latest book.
编辑让我为我的新书写一篇简短的序言。
11.precipice [pre(=betore) +cip( =head,take)头在前边的]
n. vertical or very steep face of a rock,cliff or mountain;critical situation 绝壁，悬崖；危急的处境
precipilate 猛抛下；促进；仓促的 precipitately 仓促地；陡然下降地；冷不防地
precipitalion 投下，落下；急促；降水量 precipitous 似悬崖峭壁的，陡峭的，险峻的
举例： The liffle boy climbed onto the precipice and got stranded there.
那个小男孩爬上悬崖，站在那里孤立无援。
12.preferment [(pre(=before)+fer（=carry）向前搬运]
n. the act of moving up to a higher rank or position 晋升，提升
prefer 更喜欢…preference 更喜欢；优先权；特惠 preferential 优先的；特惠的
preferable 更好的，更可取的 preferably 更好地，更可取地
举例： He is a gentleman who never sought preferment at the cost of personal integrity.
他是一位从不以牺牲自己的人格为代价去追求晋升的绅士。
13.preposterous [(pre(=before)+poster（=coming after）本来应该在后面的来到前面]
adj. with and first last and the last first;contrary to nature,reason,or common sense as to be laughable;absurd 前后颠倒的；反常的；不合理的，荒谬的
preposterously 荒谬地，不合理地
举例：He makes the preposterous claim that he is the best tennis player in the state.
他荒唐地宣称自己是那个州最优秀的网球选手。
14.precedent [pre（=before）+ced( =go)领先走]
n. something that serves as an example for the future 前例，宪例，判例
precede 领先 precedence 优先 preceding 在先的，在前的，前面的
precedented 有先例的
举例： Some say the government's decision to continue logging sets a dangerous precedent.
有人说政府继续伐木的决定开了一个危险的先例。
15.predicament [(pre(=before) +dic( =say)提前说]
n. a condition or situation that is difficult, unpleasant, embarrassing or, sometimes,comical 困境．窘境
举例： The world is in a real prodicament with the proliferation of nuclear weapons.
世界因为核武器的剧增而陷入困境。
16.premeditated [pre(=before) +med（=attend to, measure, heal）事先注意、测量]
adj. thinking out, planning or considering beforehand 事先想好的，有计划的
premeditate 预先考虑 premeditation 预先设想
举例： Her slapping you wasn't a promeditated act. She was just very angry.
她不是有意想打你，只是当时太生气了。
17.pretext [ pre(=before) +text( =weave)事先编织、编造]
n. a false reason or motive put forth to hide the real one 借口，托辞
举例： She used her mild cold as a pratext for missing work today.
今天她以轻微感冒为借口没去上班。
18.precept [(pre(=before) +cept( =take)亨先抓住]
n. moral instruction 训诫，戒律
preceptor 教师；训诫者
举例： One of the main precepts the Boy Scouts is to be "morally straight and clean".
童子军的主要戒律之一是“思想端正纯洁”。
19.precocious [pre（=before）+coc( =to mature, cook)早一点成熟]
adj. having developed certain faculties earlier than is normal 早熟的，较早具备某种能力的 precocity 早熟
举例： She's a precocious tot. She could already read at 3.
她是个早慧的孩子，三岁的时候就会读书识字了。
20.predilection [pre(=before) +di<dis( =apart) +lect( =choose)事先个别地挑出来]
n. special liking, mental preference 特别喜欢，偏爱
举例：I have a strong predilection for sweets.
我特别喜欢甜食。
21.premonition [(pre(=before) + mon（=warn, advise, remind）事先警告、使想起]
n. feeling of uneasiness considered as a warning of approaching anger, etc. 预感，预告；前兆 premonitory 预告的，前兆的
举例：I had a promonition that we were going to have an earthquake.
我预感到了我们会遭遇地震。
22.prerogative [pre( =before) +rog( =ask)比某人率先提出要求]
n. a right or privilege that belongs to a person, class, etc. according to rank or position 特权，大权
举例：lt's the mayor's prerogative to choose the 4th of July speaker each year.
迭择每年独立纪念日（7月4日）的演讲者是市长的特权。
23.pretentious [(pre(=before)+tent( =stretch)向前伸展]
adj.claiming great merit or importance 自负的；炫耀的，夸张的，虚张声势的
pretend 装作…；自称 pretense 虚伪；做作 pretension 自负，自居，虚张声势；虚饰；主张 pretender 伪装者；妄想者
举例： The people at the country club aren't protentious at all. They’re very nice!
那个乡村俱乐部的人一点都不自以为是，他们很友好！
24.precursor [(pre( =before) +curs( =run)事先、率先跑]
n. to sign; harbinger, forerunner;a predecessor as in office 征兆，预告；先驱者，先觉者；前任 precursory 先驱的；预兆的；预备的
举例：It has been said the Poe's novels were precursors to the modem detective novel.
坡的小说被认为是现代侦探小说的先驱。
25.preempt [pre（=before）+empt (=take)亨先抓住、采取]
v. obtain by preemption; occupy public land so as to have the right of preemption; do something to frustrate the aggressive plans 通过优先购买权得到；为了得到优先购买权而占有（公地）；先发制人，抢先取得，
事先获得
preemption 优先购买（权）；优先获取 preemptive 先取得的；优先购买（权） 的；先发制人的
举例： The special news bulletin preempted regular programming.
特别新闻快报取代了常规播放的节目。
26.prefatory [pre(=before)+fa( =say)先说]
adj. of a preface; introductory 序言的，前言的
preface 序言，前言
举例： Before giving my speech, l'd like to make a few pretatory remarks.
在开始演讲之前，我想先说几句开场白。
27.presage [pre(=betore) +sag( =perceive)事先感觉、感知]
v. foretell, be a sign of, predict: have a presentiment of 预告，预示，预言；预知，预感
n. omen,a feeling that something is going to happen, foretelling 前兆，预告；预感
举例： Chest and arm pains, nausea, and shortness of breath can presage a heart attack.
胸口和胳膊疼痛、恶心、呼吸困难都可能是心脏病的前兆。
28.presentiment [pre( =before) +sent( =feel)事先感觉]
n. vague feeling that something unpleasant or undesirable is about to happen 预感,直觉
举例： l've had a presentiment all day that something extraordinary is going to happen.
我一整天都感觉好像要发生什么特别的事情似的。
29.prestigious [pre( =before) +stig<string( =prick, bind)事先刺，捆绑]
adj. bringing the influence or reputation gained by one's achievement, abilities,position, etc. 出名的，闻名于世的，有名望的，名门的 prestige 名望，威望
举例： He was hired directty out of law school by a very prestigious law firm.
他一从法学院毕业就被一家有名的律师事务所录用。
30.prescience [(pre(=before)+sci( =know)事先知道]
n. apparent knowledge of things before they happen or come into being 预知，先见
prescient 预知的，有先见之明的
举例： Thanks to his prescience, he got out of the stock market betore it fell.
幸亏他有先见之明，得以在股市下跌之前脱身。
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