1. To penetrate, absorb, or soak in (to something). It takes a few hours for the mixture to sink in. If the water sinks in, it could cause your floorboards to warp or even rot.

2. By extension, to become understood; to make a lasting impression or memory. The gravity of what happened in this field 200 years ago didn't sink in until we saw actors recreating the war as it would have been fought. No matter how many times I go over it, this equation just isn't sinking in.

1. To penetrate, absorb, or soak into something. If the water sinks into the floorboards, it could warping or even rot. It takes a few hours for the mixture to sink into the skin.

2. To enter into some passive, non-functional state. Within seconds I had sunk into a deep, dreamless sleep. After staring at the swinging watch, she sank into a hypnotic trance.

3. To force, press, or impale something into someone or something. In this usage, a noun or pronoun is used between "sink" and "into." He sank the blade into the body of his enemy. The farmer sank the stakes of the fence into the ground with several swings of her sledgehammer.

4. To expend time, money, or other resources into someone or something as an investment, especially when those resources were or seem to have been squandered. In this usage, a noun or pronoun can be used between "sink" and "into." By the time the product was finally released onto the market, there was simply no way for the company to earn back what they had sunk into it. We sank a lot of hours into creating this program—if it doesn't work, I'm going to be very disappointed. The company sank so much money into me, between the training courses and masters degrees they paid for, that I feel guilty quitting.

1. Literally, to go beneath the surface of water or some other liquid. The storm punched a hole in the hull of the vessel, causing it to sink below the waves. You might expect such a heavy object to sink below the surface of any liquid, but because it is less dense than mercury, it actually floats on top of it.

2. To move or appear to move beneath or behind some object or boundary. We sat watching the sun sink below the horizon. The child sank below the table to avoid having to talk to the people his parents had invited for dinner.

3. To reach or go to a level or degree beneath some point or threshold. Temperatures are expected to sink below freezing tonight, so beware of icy roads in the morning. We can't let the power output sink below 500 kilowatts.

1. To fall or lower (oneself), as due to exhaustion, weakness, despair, etc. I came in the door and sank down onto the sofa, totally wiped from such a long day at work. I sank down to the floor and cried when I heard the news that Michael had died.

2. To move or appear to move to a lower position or location. We sat watching the stars begin to appear as the sun sank down in the sky. I sank down in my chair, trying to tune out the sound of my parents arguing.

1. To enter into a cognitive state characterized by an inability to experience pleasure as well as feelings of hopelessness, helplessness, and despondency; to become clinically depressed. Despite how many things were going well for me, I could feel myself sinking into depression again. She closed herself off from her friends and family, and the isolation caused her to sink further into her depression.

2. To enter into a period of drastic economic decline, widespread poverty, and high unemployment. Eventually the entire subprime mortgage market collapsed, causing economies around the world to sink into depression. The small country sank into depression shortly after gaining its independence.

1. To become lost to obscurity; to not be known or remembered by anyone. The poet sank into oblivion after the war, only coming back into public awareness after an archive of his works was discovered in the basement of an abandoned warehouse in East Germany. He held a rather cynical view of parenthood, believing that people only had children to avoid sinking into oblivion.

2. To enter into total unconsciousness. The last thing I remember was the doctor asking me to count to ten before the general anesthetic took effect and I sank into oblivion. He was so utterly exhausted that he sank into oblivion the moment my head hit the pillow.

1. To fall, descend, or collapse to some lower point or level. The boat was struck with another torpedo, and it sank to the bottom of the sea. They've run out of fuel, but so long as they don't encounter any strong winds, their hot air balloon should sink safely to the ground. I sank to the floor in shock when they told me that Michael had been killed.

2. To appear to move to some lower point or level. We sat watching the stars beginning to appear as the sun sank to the horizon.

3. To move or shift to some lower measurement or degree. The temperatures are supposed to sink to -10 degrees tonight! The power station's output sank to just over 200 megawatts.

4. To engage in some negative action or behavior that one or others believe is below a certain standard of dignity, principles, or integrity. Don't sink to his juvenile taunts. Just ignore him. I can't believe he would sink to spreading lies about me like that. I lost faith in the news site when they sank to posting vacuous, clickbait-driven articles.

1. To fall or submerge beneath some surface. The boat was struck with another torpedo, and it sank under the waves. The frozen lake became unstable, and the man sank under the ice.

2. To fall, descend, or collapse due to some downward pressure or force. The entire roof sank under the strain placed on it by the accumulating snowfall. The hot air balloon began to sink under the weight of so many people.