1. （尤指修理汽车的）技工，机修工，修理工
    A mechanic is someone whose job is to repair and maintain machines and engines, especially car engines.

    e.g. If you smell gas fumes or burning, take the car to your mechanic...
           如果你闻见汽油冒烟或燃烧的异味，应把车送修。
    e.g. An elevator mechanic can work the machinery directly by turning this lever.
           电梯修理工可以转动这根杠杆直接操作机器。

2. （过程、系统、动作等）运作方式;(具体的)方法，技巧
    The mechanics of a process, system, or activity are the way in which it works or the way in which it is done.

    e.g. What are the mechanics of this new process?...
           这一新工序如何操作？
    e.g. The mechanics of the job, however, have changed little since then.
           不过，工作流程从那以后就几乎没有任何变化。

3. 力学;机械学
    Mechanics is the part of physics that deals with the natural forces that act on moving or stationary objects.

    e.g. ...the other great theory of 20th-century physics, quantum mechanics...
           20世纪物理学的另一个伟大理论——量子力学
    e.g. He has not studied mechanics or engineering.
           他没有学习过力学和工程学。