1. 薄的，细的　 having a small or smaller than average distance between opposite surface; not stick
2. 稀的，稀疏的，稀少的　 (of a liquid) watery, flowing easily, not closely packed, made of few objects widely separated, easy to see through, not dense
3. 瘦的　 having little fat on the body, not fat
4. 弱的，缺乏力量的，浅薄的　 lacking in strength and fullness, not having the necessary qualities to gain the intended result; unsatisfactory

　～ time　没有钱也没有欢乐的日子
　～ in the face　脸瘦

　It's dangerous to walk on thin ice on a lake.　在湖里的薄冰上行走是很危险的。
　She should wear a thinner shirt in summer.　夏天她应该穿薄一点的衬衣。
　A thin veil of mist trailed below.　下边飘起一层薄雾。
　You ought to know better than to go out in this cold weather in those thin summer shoes; no wonder your feet got cold!　你应当明白，这么冷的天不应穿夏天的鞋出去，难怪你的脚冻坏了！
　I have thin hair.　我头发很稀。
　A thin rain began to fall.　开始稀稀落落下起雨来。
　Thick liquid pours much more slowly than thin liquid.　稠的液体倒出来比稀的慢。
　There were two girls there, a fat one and a thin one.　那儿有两个姑娘，一个胖的，一个瘦的。
　That was a thin excuse.　这是很容易被识破的托词。
　This gravy is too thin.　肉汁太清了。
　The air on the tops of high mountains is thin.　高山顶上的空气很稀薄。
　He was thin after a bout of illness.　一场病后，他又瘦又弱。
　He is thinner than you.　他比你瘦。
　Our cat was missing for days but eventually it turned up, looking a bit thinner than before.　我们的猫失踪了数天，但它终于回来了，看上去比以前瘦些。
　His excuse for being late was very thin.　他迟到的借口是无法使人相信的。
　The ice on the pond is too thin for skating.　池塘上的冰太薄，不能在上面溜冰。
　The boy was thin for his age.　就他的年龄而言，这男孩算瘦的。
　She is thin in the face.　她的脸瘦。
　The plot is rather thin for such a long story.　对这样长的故事来说，这个情节显得太单薄了。

 ♣ grow thin
　变小〔少〕　become small or less
　The margin of safety has grown thin.　安全系数已变小了。
 ♣ have a thin time
　日子过得不愉快〔舒服〕　have an unpleasant, uncomfortable or especially unsuccessful time
　He's been having rather a thin time since his wife left him.　自从他妻子离开他之后，他日子一直过得不太好。
　The team's been having a thin time of it recently—not a single win in two months.　那个队近来日子不好过——两个月里一场没赢。
 ♣ stretch thin
　快到极限了　will come to the limit
　That country's manpower and its resources are already stretched thin.　那个国家的人力和财力已快到山穷水尽的地步了。
　Seven years of war have stretched their army thin.　七年战争已使他们的兵力感到不足。
 ♣ thin end of the wedge
　开头无关紧要但后果严重的事　sth which seems unimportant but will open the way for more serious things of a similar kind
　You're letting one or two employees take days off here and there—this is just the thin end of the wedge.　你现在让雇员一个两个的随意休假，开始是无关紧要但后果却严重。
　Unions regard the government's intention to ban overtime as the thin end of the wedge.　工会认为政府禁止加班的用意看似事小，实则事大。
 ♣ thin on the ground
　稀少的，寥寥无几　not plentiful
　Taxis seem very thin on the ground tonight—we will have to walk.　今晚出租车似乎非常稀少，我们得步行了。
 ♣ wear thin
　守不住，要垮了　begin to fail
　My patience was wearing thin.　我快忍耐不住了。
　Their cloak of neutrality in the Iran-Iraq war was beginning to wear a bit thin.　他们在两伊战争中表面上所采取的中立态度开始有点露馅了。

 ♣ thin, lanky, slim, underweight
　这组词都可形容人“瘦”。其区别是：thin以中性的方式来描写人的外貌，常同营养、疾病有较多牵连，不含褒贬义；slim描写人的外貌时有瘦得很美的含义，带有褒义；lanky用来描述人又高又瘦，含有幽默的意味；underweight指描述人因吃得不好或生病而过“瘦”。例如：
　She was tall and thin, with fairish hair.　她高高瘦瘦的，留着长发。
　She used to be pretty and slim.　她过去非常漂亮苗条。
　Tom was a lanky boy with long skinny legs.　汤姆是一个腿很细的瘦高个儿。
　Many people who are underweight are happy with their size.　许多人很喜欢自己那种过于瘦的身材。
 ♣ thin, gaunt, lean, slender
　这组词都可形容人“瘦”。其区别是：thin指因病、过分劳累或缺乏营养等而缺少正常的肌肉；gaunt指因饥饿或操劳过度而呈现的枯瘦或憔悴的面庞；lean强调缺乏脂肪，指自然的瘦，其肌肉却很结实；slender可指人或动物，作“细长的，苗条的”解，有时含有“纤弱”的意思。例如：
　He has the gaunt face of a starving man.　他是一副憔悴的面容的饿汉相。
　The forest ranger is lean.　那位森林警察很结实。
　She admired Alice's slender build.　她羡慕艾丽斯那苗条的身材。
 ♣ thin, emaciated, haggard, lean, spare
　参见spare条。

　thin　还可用作副词，意思是“薄薄地，细细地；稀疏地”。例如：
　Don't cut the bread so thin.　不要把面包切得那样薄。

　vt. & vi.（使）变稀薄，（使）变稀少，（使）变细 (cause to) become thin or thinner

　～ alarmingly　使人惊恐地稀薄
　～ astonishingly　惊人地稀薄
　～ dangerously　稀薄得危险
　～ dreadfully　可怕地稀少
　～ extremely　极端地稀少
　～ terribly　可怕地稀少
　～ away　散去
　～ down　使变稀〔少，细〕，变得稀薄了，渐渐散了
　～ down paint　调稀油漆
　～ out　使稀少，使变弱，使变细，越来越弱了，渐渐稀少起来
　～ out the seedlings　间苗，拔除过多的苗

　His hair is thinning.　他的头发逐渐稀少了。
　Let's wait till the fog thins.　让我们等到雾散开为止。
　We should wait until the mist thins before driving on.　我们应当等晨雾变得稀薄了以后再开车前进。
　The crowd thinned after the parade was over.　游行结束后，人群开始散去。
　The smoke clouds were thinning away.　烟云正在散去。
　Hunger has thinned her cheeks.　饥饿已使她两颊消瘦。
　He thinned the branches of that tree.　他剪去那棵树上的一些枝叶，使其稀疏些。
　He thinned the stick with a knife.　他用小刀把那根棍子削细。
　He thinned the wine by adding water.　他往酒里兑水把它稀释。
　War and disease had thinned the population.　战争和疾病已使人口减少。

 ♣ thin down　(v.+adv.)
　（使）变细，（使）变薄，（使）变稀疏　(cause to) become less thick, dense, or crowded
　This liquid appears to have thinned down.　这液体好像变得稀薄了。
　The painter thinned the paint down with white spirit.　画家用松香油溶剂稀释颜料。
　Can you thin the paint down so that it spreads more easily?　你能不能把油漆调稀点儿?这样不好刷。
　The oppression of the invaders had thinned down the population of the village.　入侵者的压迫使这个村庄的人口减少了。
　The stream had thinned down to a mere trickle.　小河越来越窄，最后变成了涓涓细流。
　Her voice thinned down to a whisper as people turned to shush her.　当人们回过头来嘘她时，她就放低嗓门讲话了。
 ♣ thin out　(v.+adv.)
1. （使）变弱，（使）变淡，（使）变细 (cause to) become less strong or less rich
　The enemy resistance thinned out as night approached.　傍晚时，敌人的抵抗越来越弱了。
　The barber thinned out his customer's thick hair.　理发师把顾客的浓密头发削薄了些。
2. 减少；（使）不拥挤，（使）稀疏 (cause to) become less crowded or less populated
　Towards the city limits the houses begin to thin out.　靠近城市尽头的地方房屋渐渐稀少起来。
　He thinned out the seedlings.　他拔掉一些幼苗使它们变得稀疏。
　War and disease had thinned out the population.　战争和疾病使人口减少了。
　The population of the city was thinned out by the black death.　这个城市的人口由于黑死病而减少了。
3. 除去 remove surplus plants or trees
　They thinned out a stand to create a lush forest tomorrow.　他们除去了林场中多余的树木，以利来日森林长得更茂盛。

　［同义词］ adj. faint, narrow, slim, weak
　［反义词］ adj. fat, plump, strong
　［词源］　古英语thynne<拉丁语tenuis （细的，薄的）