subsist
To stay alive with only the bare minimum to survive.
To subsist means to survive with only the bare minimum of what you need to stay alive. When people subsist, they have just enough food, water, or money to keep going, but nothing extra. A family subsisting on rice and beans has enough to eat but no variety or treats. During a hard winter, animals in the forest might subsist on whatever berries or bark they can find.
The word suggests a difficult, stripped-down kind of existence. You're not thriving or comfortable when you subsist: you're just managing to stay alive. A farmer whose crops failed might subsist on stored grain until the next harvest. Explorers lost in the wilderness might subsist on roots and insects.
Subsistence (the noun form) refers to this minimal level of survival. Subsistence farming means growing just enough food for your own family to eat, with nothing left over to sell. A subsistence wage is barely enough money to pay for food and shelter, with no room for savings or extras.
When you read about people subsisting somewhere, it tells you they're in tough circumstances, getting by with very little. The word carries a sense of hardship: subsisting isn't living well, it's simply staying alive.