本文所精选的均是 SAT较难的核心词汇，尤其适用于想拿高分的同学背诵。提醒大家背诵时重视单词的英文解释，以便抓住其本质意思，并举一反三，把每个词相关的近义词，反义词和使用注意事项都掌握好。

11～20

11. adamant [ˈædəmənt]

adj. unyielding, immovable, inflexible, refusing to give in, unshakable, unrelenting, implacable. 固执的，坚决的

形容词adamant的意思衍生自其名词意思"坚硬的东西或石头"，形容词的古时写法是admantine，目前被adamant所取代。

例句：She was admant in her opposition to the plan.

12. sporadic [spəˈrædɪk]

adj. occasional, infrequent, irregular, not constant, happening from time to time, occuring in a scattered or random way. 偶尔发生的，断断续续的

反义词：constant，incessant，unremitting。

例句：

A business venture may have sporadic success.

A gamber's luck may be sporadic.

Sporadic crimes are crimes scattered throughout a city or neighborhood.

sporadic outbreaks of a disease in the population are occasional, isolated outbreaks.

13. vanguard [ˈvænɡɑːrd]

n. the forefront of an action or movement, leading position or persons in a movement. 先锋

在军事领域，vanguard意思是部队的最前列，即先头部队。其被引申为艺术，政治，工业等社会活动的领导者，先锋。

相关衍生词：avant-garde，前卫的，（艺术领域的）前卫派思想

14. concur [kənˈkɜːr]

v. 1）to agree, be in accord with, unite in opinion. 同意，赞同。“We concurred on almost every point of negotiation.2）to happen together 同时发生，近义词coincide。“His pay raise concurred with his promotion.”3）to act together, combine in having an effect 一起作用导致某种效果。 “Time and chance concurred in our success.”Concur来自于拉丁文前缀con-，表示一起，和currere，表示跑，流动，合起来意思就是一起跑或流动。

15. precociousness [prəˈkoʊʃəsnəs]

n. early development or maturity, especially in mental ability. 早熟（尤指心智方面）

形容词是precocious，来自拉丁语praecox，意思是提前成熟的 “ripening before its time.” 现在通常指儿童在智力和情感方面早熟。

反义词：retardation。

16. aloof [əˈluːf]

adj. apart, at a distance, removed, withdrawn, not wishing to speak or associate with others. 冷漠的，疏远的

同义词：unsympathetic, unapproachable, standoffish (offish), indifferent.

17. creed [kriːd]

n. belief, professed faith or opinion, especially a system of religious belief. 信念，信条，信仰

同义词：doctrine，dogma

Creed来自拉丁语credo，意思是“I believe.” 也是英语单词credo的来源。Credo和creed是同义词，区别是credo更加学术和正式，而creed是比较通用的说法。

拉丁文credo也是incredible和credulous的词源。credulous表示轻信的，和gullible是同义词。"To a credulous person, even the most outrageous tall tales seem credible."

18. tawdry [ˈtɔːdri]

adj. cheap and showy, gaudy, garish, sleazy. 廉价而俗丽的；粗俗的，下流的

传说tawdry来自于短语 “tawdry lace,” 是 “Saint Audrey lace”的变体，一种在英格兰Saint Audrey集市上售卖的蕾丝。这种蕾丝材质比较低劣，随着时间推移，意思演变为廉价又俗气。如今tawdry既可以用字面意思也可以用以修辞。“A person may wear tawdry clothing or have a tawdry reputation.”

19. arduous [ˈɑːrdʒuəs]

adj. very difficult, hard to achieve or accomplish, requiring great effort. 艰苦的，艰难的

例句：Raising children is an arduous responsibility.

同义词有：strenuous, laborious, and toilsome.

20. peevish [ˈpiːvɪʃ]

adj. irritable, cross, complaining, fretful, ill-humored and impatient, difficult to please. 爱生气的，易怒的，脾气坏的

动词或名词形式是peeve，"Her pet peeve is a wet towel left on the bed."

例句：She glared down at me with a peevish expression on her face.