1
- a mechanical or electrical device for measuring time, indicating hours, minutes, and sometimes seconds, typically by hands on a round dial or by displayed figures钟, 时钟。
1.1
the clock
time taken as a factor in an activity, especially in competitive sports（尤指体育比赛的）时间段：this stage is played against the clock.
这一段比赛争分夺秒。
1.2
- informal a measuring device resembling a clock for recording things other than time, such as a speedometer, taximeter, or milometer〈非正式〉仪表（如速度计, 计程器, 里程表）：
a car with over 82,000 miles on the clock.
里程表上显示超过82,000英里的小轿车。
2
- Brit. a downy spherical seed head, especially that of a dandelion〈英〉（尤指蒲公英的）绒毛头。
3
- Brit. informal a person's face〈英, 非正式〉人脸。
with obj. informal <非正式>
1
- attain or register (a specified time, distance, or speed)达到; 记录下（一定时间, 距离, 速度）：
Thomas has clocked up forty years service
托马斯工作已达40年了
no obj. this is a generous CD, clocking in at more than 60 minutes.这张唱片容量真大, 共计60多分钟。
1.1
- achieve (a victory)获（胜）：
he clocked up his first win of the year.
他取得了今年的第一次胜利。
1.2
- record as attaining a specified time or rate记录（时间, 速度）：
the tower operators clocked a gust at 185 mph.
塔上操作员记录下每小时185英里的风速。
2
- Brit. informal notice or watch〈英, 非正式〉注意; 看：
I noticed him clocking her in the mirror.
我注意到他在镜中审视她。
3
- informal, chiefly Brit. hit (someone), especially on the head〈非正式, 主英〉击打（某人）（尤指击打头部）：
someone clocked him for no good reason.
有人毫无理由地打了他。
4
- Brit. informal wind back the milometer of (a car) illegally in order to make the vehicle appear to have travelled fewer miles than it really has〈英, 非正式〉把（汽车）的里程表往回拨。
短语
round（或around）the clock
- all day and all night日夜不停地：
I've got a team working around the clock.
我手下有一组人日夜工作。
turn（或put）back the clock
- return to the past or to a previous way of doing things时光倒流, 回到从前; 守旧规。
watch the clock
- another way of saying CLOCK-WATCH.
词源
late Middle English: from Middle Low German and Middle Dutch klocke, based on medieval Latin clocca 'bell'.
短语动词
clock in（或〈英〉on）
- register one's arrival at work, especially by means of an automatic recording clock上班打卡记时：
staff should clock in on arrival.
员工到达时应打卡记时。
clock out（或〈英〉off）
- register one's departure from work in a similar way下班打卡记时：
she clocks off to go home.
她打卡下班回家。