1. To seep, penetrate, or absorb in (to something). It takes a few hours for the mixture to soak in. If moisture soaks into the floorboards, it could cause them to warp or rot.

2. To be immersed in some substance, especially so as to absorb or be saturated by it. Let the beans soak in the stock to become soft and flavorful. The letters had been soaking in a puddle, so the writing was completely illegible.

3. To immerse someone or something in some substance so as to make them or it thoroughly wetted or saturated. A noun or pronoun is used between "soak" and "in." You want to soak the ham in water overnight to help draw some of the salt out of the meat. They soak you in a tub full of warm mud for half an hour. It sounds gross, but it's really relaxing!

4. To become understood; to make a lasting impression or memory. The gravity of what happened in this field 200 years ago didn't soak in until we saw actors recreating the war as it would have been fought. I was so stunned that none of what the police officer told me soaked in.