1. 黏土;陶土
    Clay is a kind of earth that is soft when it is wet and hard when it is dry. Clay is shaped and baked to make things such as pots and bricks.

clay的解释

    e.g. ...the heavy clay soils of Cambridgeshire...
           剑桥郡的重黏土质土壤
    e.g. As the wheel turned, the potter shaped and squeezed the lump of clay into a graceful shape.
           随着陶轮的转动，制陶工人缓慢挤压陶泥块，塑出优美的造型。

2. 红土网球场;沙地网球场
    In tennis, matches played on clay are played on courts whose surface is covered with finely crushed stones or brick.

clay的解释

    e.g. Most tennis is played on hard courts, but a substantial amount is played on clay...
           多数网球比赛在硬地球场上举行，不过也有相当数量的比赛在红土球场上进行。
    e.g. He was a clay-court specialist who won Wimbledon five times.
           他是红土场上的专家，曾5次在温布尔登夺冠。

3. （受人崇仰的人的）不为人知的严重缺点(或缺陷)
    If you say that a person who is respected or admired has feet of clay or has clay feet, you mean that they have serious faults which you or other people did not know about before.

    e.g. When those idols are found to have feet of clay, the pain of disenchantment can be profound.
           当人们发现那些偶像有严重的缺陷时，会产生无比痛苦的失落感。