mire
Thick, sticky mud that is hard to walk through.
Mire is thick, deep mud that's difficult to move through. When you step into a mire, your feet sink down and the mud grips your boots, making each step exhausting. A hiker might accidentally wander into a mire near a swamp and struggle to pull their legs free with each step forward.
The word also describes getting stuck in a difficult situation that's hard to escape. A student might find themselves mired in a complicated math problem, unable to see the way forward. A family planning a vacation could get mired in arguments about where to go, with everyone pulling in different directions and no decision getting made. A company might become mired in debt, unable to break free from financial troubles.
That physical image of being stuck in deep mud helps explain the feeling of being mired in problems: you're working hard but not making progress, and everything feels heavy and difficult. When someone says a project is mired in delays, they mean it's stuck, and moving forward feels almost impossible.