The noun 桶 (tǒng) means "bucket" or "barrel" and refers to a container for holding liquids or other materials. It can be modified by size or content descriptors, as in 大水桶 (big water bucket).
他提着一桶水去洗车了。
tā tí zhe yī tǒng shuǐ qù xǐ chē le.
He carried a bucket of water to go wash the car.
厨房里放着两个空桶。
chúfáng lǐ fàng zhe liǎng gè kōng tǒng.
There are two empty buckets in the kitchen.
这个桶太重了,我搬不动。
zhège tǒng tài zhòng le, wǒ bān bù dòng.
This bucket is too heavy — I can't move it.