1. 粗略地看;快读;浏览
    When you scan written material, you look through it quickly in order to find important or interesting information.

    e.g. She scanned the advertisement pages of the newspapers...
           她浏览了一下报纸的广告页。
    e.g. I haven't read much into it as yet. I've only just scanned through it.
           我还没有细细研读，只是粗略地翻看了一下。

2. 细看;察看;审视;端详
    When you scan a place or group of people, you look at it carefully, usually because you are looking for something or someone.

    e.g. The officer scanned the room...
           那名警官仔细检查了房间。
    e.g. She was nervous and kept scanning the crowd for Paul...
           她很紧张，眼睛不停地在人群中搜寻保罗。

3. (用机器)扫描(行李等)
    If people scan something such as luggage, they examine it using a machine that can show or find things inside it that cannot be seen from the outside.

    e.g. Their approach is to scan every checked-in bag with a bomb detector.
           他们的方法是用炸弹探测器对每一个办理了登机手续的箱包进行扫描。

4. 扫描(磁盘以查毒)
    If a computer disk is scanned, a program on the computer checks the disk to make sure that it does not contain a virus.

    e.g. The disk has no viruses — I've scanned it already.
           这个盘没有感染病毒——我已经扫描过了。

5. 扫描(照片或文件)
    If a picture or document is scanned into a computer, a machine passes a beam of light over it to make a copy of it in the computer.

    e.g. The entire paper contents of all libraries will eventually be scanned into computers...
           所有图书馆的全部纸质内容最终都会被扫描进电脑。
    e.g. Designs can also be scanned in from paper.
           设计图也可以从纸上扫描进电脑。

6. (雷达、声呐等)扫描，扫掠
    If a radar or sonar machine scans an area, it examines or searches it by sending radar or sonar beams over it.

    e.g. The ship's radar scanned the sea ahead.
           船上的雷达扫描了前方的海域。

7. (医疗)扫描检查
    A scan is a medical test in which a machine sends a beam of X-rays over a part of your body in order to check that it is healthy.

    e.g. He was rushed to hospital for a brain scan.
           他被火速送往医院做脑部扫描。
    e.g. ...a breast scan to check for cancer.
           为诊察癌症所做的乳腺扫描检查

8. 胎儿扫描检查
    If a pregnant woman has a scan, a machine using sound waves produces an image of her womb on a screen so that a doctor can see if her baby is developing normally.

9. (诗)符合格律，韵节合拍
    If a line of a poem does not scan, it is not the right length or does not have emphasis in the right places to match the rest of the poem.

    e.g. He had written a few poems. Sid told him they didn't scan.
           他写了几首诗。锡德告诉他那几首诗都不押韵。