1. 内裤
    Pants are a piece of underwear which have two holes to put your legs through and elastic around the top to hold them up round your waist or hips.

    e.g. I put on my bra and pants.
           我戴上乳罩，穿上内裤。

2. 裤子
    Pants are a piece of clothing that covers the lower part of your body and each leg.

    e.g. He wore brown corduroy pants and a white cotton shirt.
           他身着棕色灯芯绒裤子和白色棉衬衫。

3. 劣质品
    If you say that something is pants, you mean that it is very poor in quality.

    e.g. The place is pants, yet so popular.
           那个地方很糟糕，却很受欢迎。

4. 使…（烦）得要死；把…（吓）得要命
    If someone bores, charms, or scares the pants off you, for example, they bore, charm, or scare you a lot.

pants

    e.g. You'll bore the pants off your grandchildren...
           你会把孙辈们烦透的。
    e.g. We all love to frighten the pants off ourselves by going on hair-raising rides at funfairs.
           我们都喜欢乘坐游乐场那些让人毛发直竖的游乐设施，把自己吓得魂不附体。

5. 凭感觉；凭直觉
    If you fly by the seat of your pants or do something by the seat of your pants, you use your instincts to tell you what to do in a new or difficult situation rather than following a plan or relying on equipment.

6. to be caught with one's pants down -> see catch
    to wear the pants -> see wear