the thumb (as a body part)
拇指是手指中最短但最粗的。
She accidentally hit her thumb with a hammer.
她不小心用锤子砸到了拇指。
手上最短最粗的手指,人类活动度最大,可与其他所有手指对握。；滑块上可沿直线移动的部分。；手套的拇指部分；挖掘机铲斗的顶部盖板,用于在铲取物料后防止其溢出。；凸形线脚,截面呈四分之一圆或椭圆
the short, thick finger on the side of the hand
手上最短最粗的手指,人类活动度最大,可与其他所有手指对握。
The shortest and thickest digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers.
拇指
the thick short innermost digit of the forelimb
滑块上可沿直线移动的部分。
The part of a slider that may be moved linearly along the slider.
手套的拇指部分
the part of a glove that provides a covering for the thumb
挖掘机铲斗的顶部盖板,用于在铲取物料后防止其溢出。
A top hatch plate for covering an excavator bucket, used to keep material in the digger bucket after scooping it up, and not letting it spill out.
凸形线脚,截面呈四分之一圆或椭圆
a convex molding having a cross section in the form of a quarter of a circle or of an ellipse
He accidentally hit his thumb with a hammer while fixing the shelf.
他修理架子时不小心用锤子砸到了拇指。
用法提示：此处 thumb 为名词，指手指的拇指。
She held the needle between her thumb and index finger.
她用拇指和食指捏住针。
用法提示：此处 thumb 为名词，表示拇指，用于描述抓握动作。
The toddler sucked his thumb for comfort.
那个幼儿吮吸拇指以求安慰。
用法提示：此处 thumb 为名词，指拇指，常用于儿童安抚行为。
拇指是手指中最短但最粗的。
She accidentally hit her thumb with a hammer.
她不小心用锤子砸到了拇指。
固定习语，意为‘经验法则’。
As a rule of thumb, you should drink eight glasses of water a day.
根据经验法则，每天应该喝八杯水。
表示赞成或反对的手势。
The movie received a thumbs up from critics.
这部电影获得了评论家的好评。
‘digit’是‘finger’和‘toe’的统称，不特指拇指，但在解剖学上可指包括拇指在内的手指。
在日常用语中，‘finger’通常不包括拇指；但在某些语境（如手套尺寸）中，拇指也可被归为finger。
grammar · medium
易错句子I hurt my finger.
正确表达I hurt my thumb.
中文的‘手指’通常包括拇指，但英语中‘finger’特指除拇指外的手指。当具体指拇指时，应使用‘thumb’。
grammar · medium
易错句子He thumbed for a ride on the highway.
正确表达He thumbed a ride on the highway.
动词‘thumb’在表示‘搭便车’时是及物动词，直接跟‘a ride’，不需要介词‘for’。
拇指的对立手指，位于手部最外端
thumb 是拇指，thump 是重击；拼写相似但意义不同。
thumb 是拇指，thumbtack 是图钉；thumbtack 包含 thumb 但指不同的物品。
thumb 是拇指（手指的一种），finger 泛指手指；在计数等场景中有时可互换但拇指特指。
可对生的拇指
The opposable thumb allows humans to grip objects.
可对生的拇指使人类能够抓握物体。
经验法则
As a rule of thumb, you should add 10% to the estimated time.
根据经验法则，你应该在预计时间上增加10%。
园艺才能
My grandmother has a green thumb; her garden is always full of flowers.
我祖母有园艺才能，她的花园总是开满鲜花。
拇指受伤
He missed the game due to a thumb injury.
他因为拇指受伤错过了比赛。
吸拇指
The child still sucks his thumb when he is tired.
那个孩子累的时候还会吸拇指。
伸出拇指搭车
They stuck out their thumbs hoping for a ride.
他们伸出拇指希望搭车。
经验法则；粗略估计
As a rule of thumb, you should drink eight glasses of water a day.
根据经验法则，你每天应该喝八杯水。
园艺才能；绿手指
My grandmother has a green thumb; her garden is always beautiful.
我祖母有园艺才能，她的花园总是很漂亮。
笨手笨脚
I'm all thumbs when it comes to fixing things.
我在修理东西时笨手笨脚。
两个拇指竖起来！（表示赞许）
The movie got two thumbs up from critics.
这部电影获得了评论家的两个大拇指。
拇指姑娘，拇指姑娘，小小的人儿。
She was named Thumbelina because she was as small as a thumb.
她被命名为拇指姑娘，因为她像拇指一样小。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.