1. S 底部，基部，下端，末尾；水底　 the lowest part of sth; the ground under the sea, a lake, or a rover
2. C （东西的）底　 the base on which sth stands
3. S 尽头，末端　 the far end
4. S 根源，起因　 the starting point; cause or origin
5. C 臀部，屁股　 the part of the body on which one sits
6. S 最无关紧要的部分　 the least important, least valuable, or least favourable part of anything; the lowest level

　clean the ～　清扫底部
　go to the ～　沉没
　reach the ～　到达底部
　see the ～　看到底
　send to the ～　打沉，弄沉
　sink to the ～　沉到底
　swim to the ～　游下去
　touch ～　达到最低点，查核事实
　get at the ～ of the affair　调查这事的真相
　get to the ～ of　弄清…的真相
　get to the ～ of an affair　弄清事情的原委
　hit ～　到达最低点，生活得不能再坏
　knock the ～ out of the theory　证明这个学说无价值
　know the ～ of everything　彻底了解一切
　stand on one's own ～　自立
　double ～　双层底
　false ～　假底
　hard ～　硬底
　lake ～　湖底
　river ～　河底
　sea ～　海底
　baby's ～　婴儿的臀部
　ship's ～　船底
　at ～　实际上，基本地
　at the ～　在底部，实质上
　at the ～ of a page　书面的下端
　at the ～ of one's heart　心底里
　at the ～ of the well　井底
　from the ～ of one's heart　发自内心，诚心诚意
　in the ～ of　在…底部
　in the ～ of the cup　在茶杯的底部
　on the ～　在底部，实质上
　ship with double ～　双底船
　～ of the affair　真正原因
　～ to　…的底
　～ to the suitcase　箱子底

　The bottom of the nest is laid with feathers and hair.　巢的底部是用羽毛和头发铺成的。
　She smacked a child's bottom.　她打孩子的屁股。
　You'd better stop up the small hole at the bottom of your wash-basin.　你最好堵上你洗脸盆底上的小洞。
　The sleds rested at the bottom of the hill.　那些雪橇停在山脚下。
　Dregs settled at the bottom of the container.　渣滓沉淀在容器的底部。
　She drew up her horse at the bottom of the hill.　她在小山底下突然把马勒住。
　Our team was at the bottom of the local competition, but now they are drawing ahead.　在地方赛中我们队落在最后，可现在却一马当先。
　He is always at the bottom of the class.　他的成绩在班上总是排在最末。
　Add the other items on at the bottom of the page.　请把其他几项加在这一页的末尾。
　Sign your name at the bottom of the page, please.　请在这页的最下端签名。
　He could discern a faint light at the bottom of the forest.　他能看到在森林的尽头有一线微弱的灯光。
　From the bottom of the stairs Mary called up, "Have you seen my glasses?"　玛丽在楼底下朝楼上大声地问：“你有没有看到我的眼镜?”
　A stream issued from the bottom of the hill.　一条小溪自山脚下流出。
　He works from the bottom of his heart.　他诚心诚意地工作。
　I want to tell you from the bottom of my heart that I am truly sorry.　我从心底向你表示真诚的歉意。
　The water drained out of the flower-pot through the hole in the bottom.　水从花盆底部的洞漏出去。
　Can you see where the rust has begun eating into the bottom of the driver's door?　你能看得出铁锈是从哪儿开始侵蚀到司机座旁的那扇门底部吗?
　The hunters camped near the bottom of the mountain.　猎人们在山根附近设营。
　Through the clear water, we could see fish on the bottom.　通过清澈的水，我们能看见水底的鱼。
　We stood on the bottom of the hill, drinking in the beautiful view.　我们站在山脚下，观看这美丽的风景。
　Come to the bottom of the ladder and chuck up the other brush, will you?　爬下梯子，把另一把刷子扔上来，好吗?
　After going to the hill bottom, I sat down to catch my breath.　走到山脚下之后我坐下来歇一口气。
　Go down to the bottom of the page and then stop.　念到这一页底下停止。
　He drained the cup of sorrow to the bottom.　他饱尝了悲伤的痛苦。
　They explored the bottom of the sea.　他们勘测了海底。
　The children were knocking the bottom of the box.　孩子们在敲箱子底。
　You support the bottom of the box while I lift the top.　你托着箱子底，我抬上部。
　The bottom of the candle is fused with its holder.　蜡烛的底部和烛台熔合在一起。
　Block out the bottom of this picture when it is printed; the balance of the page will be better.　印刷时，这幅画的底部要遮住不印出来，那样画面的布局就会更加匀称。
　He measured Mrs. Brown from top to bottom.　他把布朗太太上下打量了一番。
　He was spotted with mud from top to bottom.　他全身都是污泥斑点。

 ♣ bottoms up　
　干杯　empty one's glasses
　Bottoms up, brothers!　兄弟们，干杯！
　He drank his whiskey almost bottoms up.　他把杯中的威士忌饮得几乎一滴不剩。
 ♣ get to the bottom of 　
　弄清…底细　find out details of sth
　We must get to the bottom of the matter.　我们必须弄清这件事的内情。
 ♣ knock the bottom out of 　
　破坏；驳倒　destroy the sense of; prove an argument to have no value
　When the next speaker produced all those facts, he knocked the bottom out of my arguments.　当下一位发言人提出所有事实时，他把我的论点彻底驳倒了。

1. A 底部的，基部的，下端的，末尾的　 pertaining to the bottom lowest
2. A 根本的　 basal

　～ bitterness　屁股的疼痛
　～ limits　底限
　～ rock　水下岩石
　the ～ cause　根本病因
　the ～ corner　底角
　the ～ drawer　最下面的抽屉
　the ～ price　最低底价
　the ～ shelf　底层的书架

　What's your bottom price?　你能接受的最低底价是多少?
　We must keep the currency above the float's bottom limits.　我们必须使货币保持在浮动底线之上。
　The bottom candidates were dropped until only six remained.　得票最少的几个人依次被淘汰，到最后只剩下6个人。
　He numbered the pages in the bottom corner.　他把页码写在底角。
　The little boy can get at the bottom book in the stack.　小孩能得到一堆书当中的底下一本。
　Please dust all the books on the bottom shelf.　请把底层的书掸一掸。
　Her back was aching from having to get down in order to put things in and out of the bottom drawer.　由于必须弯下腰来从最下面的抽屉中把东西拿进拿出，她腰酸背痛了。
　An underwater worker watched to give one bottom time.　一名水下工作人员标出海底逗留时间。
　This is a bottom rock.　这是水下岩石。
　The woman's illness puzzled the doctor; he couldn't find the bottom cause.　那女人的病难住了医生，他找不出根本的病因。
　The bottom death cause of Marilyn Monro hasn't been found out.　玛丽莲·梦露的根本死因仍未弄清。
　A result may flow from the bottom cause.　一个结果是由根本原因造成的。
　It has been proved that the bottom cause operated to bring about the accident.　已经证实引起这次事故的根本原因。
　The teacher tried to analyse the bottom cause of our failure.　教师设法仔细分析我们失败的根本原因。
　A committee was constituted to investigate the bottom cause of the accident.　成立了一个委员会，调查事故发生的根本原因。
　Have you determined the bottom cause of the explosion?　你判定爆炸的根本原因了吗?

1. vt.给…装上底　 make sth have a bottom
2. vi.降到最低　 reach the lowest part of anything
3. vt.对…寻根问底；为…提供根据　 find out the cause

　～ a saucepan　给长柄平底锅装底
　～ sb's motives　追寻某人的动机
　～ complacently　自鸣得意地给…装上底
　～ delicately　微妙地为…提供根据
　～ probably　可能对…寻根问底
　～ reasonably　合理地给…装上底
　～ reluctantly　不情愿地对…寻根问底
　～ superficially　表面上为…提供根据
　～ voluntarily　自愿地为…提供根据
　～ out　到达最低
　～ on　使基于，到达底部

　He wanted to bottom a saucepan.　他想给长柄平底锅装底。
　His boss is bottoming his motives.　他的老板正在追寻他的动机。
　A gentleman should never bottom another person's motives unless he has good reason for doing so.　绅士绝不应该追寻别人的动机，除非他有足够的理由这样做。

 ♣ bottom on　(v.+prep.)
1. 使基于 form sth using sth as the starting point
　〔说明〕 bottom on常用于被动结构。
　The theory is bottomed on questionable assumptions.　这一理论是建立在靠不住的假设基础上的。
2. 到达底部 reach the bottom of sth
　He has bottomed on the bed of the sea.　他已经下到海底。
　They bottomed a submarine on the ocean floor.　他们驾潜艇下沉到洋底。
 ♣ bottom out　(v.+adv.)
　到达最低　reach the lowest part of anything
　The valley bottomed out by the river.　山谷在这条河附近处于最低位置。
　The value of our oil shares on the Stock Market has now bottomed out.　在证券市场上我们的石油股票价值已降到最低标准。

　［同义词］ n. base, butt, end, underneath adj. basal v. base
　［反义词］ n. top adj. top
　［词源］　古英语botm（底）