池 (chí) means "pond" or "pool" and refers to a small body of still water. It appears in compound words such as 池塘 (chítáng, "pond") and 游泳池 (yóuyǒngchí, "swimming pool"). In classical poetry, 池 on its own is sufficient to describe a garden pond.
院子里有一个小池,养了几条金鱼。
Yuànzi lǐ yǒu yī ge xiǎo chí, yǎng le jǐ tiáo jīnyú.
There is a small pond in the yard with a few goldfish in it.
夏天的时候,池里开满了荷花。
Xiàtiān de shíhou, chí lǐ kāi mǎn le héhuā.
In summer, the pond is full of lotus flowers.
孩子们喜欢在游泳池里玩水。
Háizimen xǐhuān zài yóuyǒngchí lǐ wán shuǐ.
The children love playing in the swimming pool.