log¹ ◙ noun 1. a part of the trunk or a large branch of a tree that has fallen or been cut off • 原木，圆材 2. (也作 logbook)an official record of events during the voyage of a ship or aircraft • （航海或飞行）日志 »a ship's log. 航海日志。 a regular or systematic record of incidents or observations • 观察记录 »keep a detailed log of your activities. 对你的行动作细致的观察记录。 3. an apparatus for determining the speed of a ship, originally one consisting of a float attached to a knotted line that is wound on a reel, the distance run out in a certain time being used as an estimate of the vessel's speed • 计程仪；测速仪 ◙ (logged, logging), [with obj.] 1. enter (an incident or fact) in the log of a ship or aircraft or in another systematic record • 记录（航海，飞行情况） »the incident has to be logged. 必须把事故记录下来。 »the red book where we log our calls. 记录我们呼叫的红本子。 (of a ship or aircraft) achieve (a certain distance or speed) • （船，飞机）达到（一定的距离，速度） »she had logged more than 12,000 miles since she had been launched. 自她下水以来航程已达12,000英里。 (of an aircraft pilot) attain (a certain amount of flying time) • （飞行员）达到（一定的飞行时间） 2. cut down (an area of forest) in order to exploit the timber commercially • （商业性）砍伐（林区）
【IDIOMS】
◘ (as) easy as falling off a log 1. [informal] very easy • [非正式] 易如反掌
【语源】
1. Middle English (in the sense 'bulky mass of wood'): of unknown origin; perhaps symbolic of the notion of heaviness. Sense 3 originally denoted a thin quadrant of wood loaded to float upright in the water, whence 'ship's journal' in which information from the log board was recorded
【PHR V】
◘ log in (或 on) 1. go through the procedures to begin use of a computer system, which includes establishing the identity of the user • 进入（系统），注册，登录 ◘ log off (或 out) 1. go through the procedures to conclude use of a computer system • 退出（系统），注销log² ◙ noun 1. short forlogarithm: • logarithm 的简称 »[as modifier] log tables. 对数表。 »[prefixed to a number or algebraic symbol] log x. x的对数。