Untroubled means calm and free from worry, anxiety, or disturbance. When someone has an untroubled mind, they're not stressed or upset about anything. They feel peaceful and content.

You might notice an untroubled expression on your friend's face when they've finished all their homework early and can relax for the evening. A person sleeping an untroubled sleep isn't tossing and turning or having nightmares. They're resting deeply and peacefully.

The word often describes a state of mind that comes from either not having problems or choosing not to let problems disturb you. A student might seem untroubled by an upcoming test because they studied thoroughly and feel confident. Or someone might remain untroubled by a rainy day because they find ways to enjoy themselves indoors.

When we say someone lives an untroubled life, we usually mean they experience little stress or hardship, though it can also suggest they're fortunate enough not to worry about difficulties that affect others. The word captures that enviable feeling of being at peace, whether for a moment or for longer stretches of time.