1. To plunge someone or something under the surface of a liquid, especially some body of water. I submerged myself under the surface of the lake to avoid detection by the guards. The heavy winds ended up capsizing the boat and submerging it under the waves.

2. To cover someone or something with a liquid, either fully or partially. Used especially in passive constructions. Half the town was left submerged under mud and debris after the hurricane. The entire cave is submerged under water, so we'll need scuba equipment to access it.

3. To obscure, obfuscate, or drowned out something with or through something else. The candidate is very good at submerging criticism under virulent attacks on her opponents. There are worries that recovery efforts will end up being submerged under the violent outbursts between the two countries.

4. To overwhelm, overpower, or overburden someone with something. Used especially in passive constructions. I just feel like I'm being submerged under all these different responsibilities. You can't start submerging the system under all these layers of complexity and expect it to work as it was originally intended.