1. 在水下；在水中
Something that exists or happens underwater exists or happens below the surface of the sea, a river, or a lake.

2. 供水下用的
Underwater devices are specially made so that they can work in water.

1. growing or remaining under water

e.g. viewing subaqueous fauna from a glass-bottomed boat
submerged leaves

Synonym: subaqueoussubaquaticsubmergedsubmersed

2. beneath the surface of the water

e.g. submerged rocks

Synonym: submergedsubmersed