hard

difficult, hard

这两个形容词均有“困难”之意。
difficult: 比hard较为正式，侧重需要特别的能力、智力、判断力、技巧或勇气才能克服障碍。也可指深奥或抽象的难题。
hard: 含义广，通俗用词，与easy相对，泛指任何难理解，不好处理或不易做的事。

形容词 hard:

1. not easy; requiring great physical or mental effort to accomplish or comprehend or endure
   同义词：difficult
2. dispassionate;
3. resisting weight or pressure
4. very strong or vigorous
   同义词：knockout, severe
5. characterized by toilsome effort to the point of exhaustion; especially physical effort
   同义词：arduous, backbreaking, grueling, gruelling, heavy, laborious, operose, punishing, toilsome
6. produced without vibration of the vocal cords
   同义词：unvoiced, voiceless, surd
7. (of light) transmitted directly from a pointed light source
   同义词：concentrated
8. (of speech sounds); produced with the back of the tongue raised toward or touching the velum
9. given to excessive indulgence of bodily appetites especially for intoxicating liquors
   同义词：intemperate, heavy
10. being distilled rather than fermented; having a high alcoholic content
    同义词：strong
11. unfortunate or hard to bear
    同义词：tough
12. dried out

副词 hard:

1. with effort or force or vigor
2. with firmness
   同义词：firmly
3. earnestly or intently
4. causing great damage or hardship
   同义词：severely
5. slowly and with difficulty
6. indulging excessively
   同义词：heavily, intemperately
7. into a solid condition
8. very near or close in space or time
9. with pain or distress or bitterness
10. to the full extent possible; all the way

1. The ground is as hard as stone after the drought.
   长期乾旱之後土地硬得就像石头一样。
2. Don't be too hard on her she's very young.
   别对她太严了－－她还小呢。
3. They work very hard.
   他们工作非常努力。
4. That was a hard time.
   那是一段艰难的日子。
5. It's hard to know what he's really thinking.
   很难知道他真正在想什么。

hard

adj.（形容词）
hard.er,hard.est 缩写 h.,H.
Resistant to pressure; not readily penetrated.
坚固的：对有压力的；有抵抗性的

Physically toughened; rugged.
身体结实的；强健的
Mentally toughened; strong-minded.
坚韧的：有独到见解的；意志坚强的

Requiring great effort or endurance:
困难的：要求巨大的努力和耐心的：
例句：
a hard assignment.
困难的任务

Performed with or marked by great diligence or energy:
勤奋的：需要巨大的努力和精力完成的：
例句：
a project that required years of hard work.
一项需要多年艰苦劳动的工程

Difficult to resolve, accomplish, or finish:
难以解决的：难对付的、难解决的或难以完成的：
例句：
That was a hard question.
那是一道难题

Difficult to understand or impart:
难以理解的，难以传授的：
例句：
Physics was the hardest of my courses. Thermodynamics is a hard course to teach.
物理学是我所学课程中最难理解的一门；热力学是非常难教的一门课

Intense in force or degree:
猛烈的：力量或程度上激烈的：
例句：
a hard blow.
猛烈的一击

Inclement:
严酷的：
例句：
a long, hard winter.
漫长而严酷的冬季

Stern or strict in nature or comportment:
严格的，严厉的：在性格或行为举动方面严格的或严厉的：
例句：
a hard taskmaster.
严厉的监工

Resistant to persuasion or appeal; obdurate.
倔强的，冷酷无情的：对信念或呼吁进行抵抗的；冷酷无情的
Making few concessions:
毫不让步的：
例句：
drives a hard bargain.
进行一场苛刻的交易

Difficult to endure:
难以忍受的：
例句：
a hard life.
令人无法忍受的生活

Oppressive or unjust in nature or effect:
刻薄的，苛刻的：在性格或外表上暴虐压制的或不公平的：
例句：
restrictions that were hard on welfare applicants.
这些限制对于那些福利申请人来讲实在太刻薄了

Lacking compassion or sympathy; callous.
冷淡的：缺乏热情或同情心的；冷酷的

Harsh or severe in effect or intention:
严厉的：在企图或结果上严重或严厉的：
例句：
said some hard things that I won`t forget.
说了些令我不能忘却的严厉的事情

Bitter; resentful:
怨毒的；怨恨的：
例句：
No hard feelings, I hope.
我希望没有怨恨的情绪

Causing damage or premature wear:
引起损坏的，过早磨损的：
例句：
Snow and ice are hard on a car`s finish.
冰和雪会破坏汽车表面的光泽度

Bad; adverse:
坏的；背运的：
例句：
hard luck.
坏运气

Proceeding or performing with force, vigor, or persistence; assiduous:
勤奋的：用力量、精力或耐心来进行或完成的；勤奋的：
例句：
a hard worker.
勤奋的工人

Real and unassailable:
有力的：确凿的且不容置疑的：
例句：
hard evidence.
有力的证据

Definite; firm:
确定的；强有力的：
例句：
a hard commitment.
明确的承诺

Close; penetrating:
严密的；透彻的：
例句：
We need to take a hard look at the situation.
我们需要对情况进行周密的调查

Free from illusion or bias; practical:
公正的，实际的：抛开幻想和偏见的；实际的：
例句：
brought some hard common sense to the discussion.
将实际的常识带到讨论中来

Using or based on data that are readily quantified or verified:
严密的：运用或基于事先计算或证明的数据：
例句：
the hard sciences.
严密的科学

Marked by sharp outline or definition; stark.
刻板的：由严格的提纲或概念规定的；刻板的
Lacking in delicacy, shading, or nuance.
不精密的、不灵活或缺乏变化的

Metallic, as opposed to paper. Used of currency.
金属的而非纸的。用于货币流通
Backed by bullion rather than by credit. Used of currency.
以金银为凭的：以金银储备而不是银行存款为凭证的。用于货币流通
High and stable. Used of prices.
高而稳定的。用于价格

Durable; lasting:
耐用的；持久的：
例句：
hard merchandise.
耐用的商品

Written or printed rather than stored in electronic media:
书写的：手写或打印而不用电子传播媒介的：
例句：
sent the information by hard mail.
将这条信息用手写信件送出去

Erect; tumid. Used of a penis.
竖起的：坚挺的；肿胀的。用于描写男性生殖器

Having high alcoholic content; intoxicating:
含大量酒精的；使醉的：
例句：
hard liquor.
烈酒

Rendered alcoholic by fermentation; fermented:
发酵的：通过发酵产生酒精的；发酵的：
例句：
hard cider.
苹果酒

Containing dissolved salts that interfere with the lathering action of soap. Used of water.
含无机盐的：含有参与肥皂起沫过程的溶解的盐的。用于水
Linguistics Velar, as inc in cake or g in log, as opposed to palatal or soft.
【语言学】 硬音的：与软音或软腭音相反的硬腭音，如cake（蛋糕） 一词中 c 的发音或 log（原木） 一词中 g 的发音
Physics Of relatively high energy; penetrating:
【物理学】 高透力的：具有相对高能量的；有穿透力的：
例句：
hard x-rays.
高透力Ｘ射线

High in gluten content:
麸质含量高的：
例句：
hard wheat.
硬粒小麦

Chemistry Resistant to biodegradation:
【化学】 对生物腐蚀有抵抗力的：
例句：
a hard detergent.
抗腐蚀清洁剂

Physically addictive. Used of certain illegal drugs, such as heroin.
麻醉品：肉体上上瘾的。用于如海洛因等特定的非法麻醉品
Resistant to blast, heat, or radiation. Used especially of nuclear weapons.
抗热的，抗辐射的：防爆、防热或防辐射的。尤用于核武器
adv.（副词）
With strenuous effort; intently:
努力地；拼命地：
例句：
worked hard all day; stared hard at the accused criminal.
一整天都在努力地工作；恶狠狠地盯着那个被控告的罪犯

With great force, vigor, or energy:
用力量、精力或能量地：
例句：
pressed hard on the lever.
猛烈地压在控制杠上

In such a way as to cause great damage or hardship:
剧烈地，苦难的：造成巨大破坏或困难地：
例句：
industrial cities hit hard by unemployment.
工业城市遭到失业的剧烈打击

With great distress, grief, or bitterness:
痛苦、苦闷或悲伤地：
例句：
took the divorce hard.
痛苦地接受离婚

Firmly; securely:
牢固地；安全地：
例句：
held hard to the railing.
紧紧地抓住栏杆

Toward or into a solid condition:
趋干或成为固体状态：
例句：
concrete that sets hard within a day.
混凝土在一天内就可以凝固

Near in space or time; close:
接近地：在时间或空间上相近的；接近地：
例句：
The factory stands hard by the railroad tracks.
工厂座落在铁路沿线

Nautical Completely; fully:
【航海】 完全地；完整的：
例句：
hard alee.
完全地向下风

<习惯用语>hard and fast
Defined, fixed, and invariable:
严格规定的、刻板的和无变化的：
例句：
hard and fast rules.
严格的规定

hard of hearing
Having a partial loss of hearing.
听觉障碍：部分地失去听觉能力的
One who has a partial loss of hearing.
部分地失去听觉能力的人
hard put
Undergoing great difficulty:
陷入困境：
例句：
Under the circumstances, he was hard put to explain himself.
在这种情况下，他很难为自己辩解

hard up【非正式用语】
In need; poor.
短缺：在急需中；贫困
来源：
Middle English
中古英语
from Old English heard * see kar-
源自 古英语 heard *参见 kar-

<参考词汇><同义词>hard,difficult,arduousThese adjectives are compared as they mean requiring great physical or mental effort to do, achieve, or master.
比较而言这些形容词都意为为做某事、得到或掌握某物而付出肉体或精神上的努力。
Hard is the most general term:
Hard 是最常见的：
例句：
Why is it so hard for you to keep a secretô
为什么保守秘密对你来说如此之难？

例句：
.You write with ease to show your breeding,/But easy writing`s curst hard reading. (Richard Brinsley Sheridan).
.轻轻松松地写，从而表现你的教养,/但是轻松地写是困难地读的祸根. （理查·布林斯利·谢里登）。

Difficult andhard are interchangeable in many instances:
Difficult 和hard 这两个词在许多情况下是可以互换使用的：
例句：
a difficult (or hard ) subject;
困难的（或 hard ） 课题；

例句：
a book that is difficult (or hard ) to find. Difficult, however, is often preferable where the need for skill or ingenuity is implied:
很难找的一本书（或 hard ） 。 然而Difficult一词在需要技术独创性的情况下，常会被使用：

例句：
.All poetry is difficult to read,/—The sense of it is, anyhow. (Robert Browning).
.诗歌总是难读的／无论如何，它的意义如此. （罗伯特·布朗宁）。

Arduous refers to what involves burdensome labor or sustained physical or spiritual effort:
Arduous 指需要付出难于忍受的劳动或持续的肉体上或精神上的努力的：
例句：
.knowledge at which[Isaac] Newton arrived through arduous and circuitous paths. (Macaulay).
.艾萨克·牛顿经过艰辛的和曲折的道路所得到的 知识. （麦考利）。

例句：
Negotiating a reduction in nuclear arms is a long and arduous undertaking. See also Synonyms at firm
有关削减核武器的谈判是一项漫长而艰苦的工作 参见同义词 firm