To toss means to throw something lightly or casually, usually without much force or careful aim. When you toss a ball to a friend across the room, you're not winding up for a powerful throw: you're just lobbing it gently their way. You might toss a wadded-up paper into the recycling bin, toss a salad by mixing it with large spoons, or toss your jacket onto a chair when you get home.

The word suggests something relaxed and informal. A quarterback throws a long pass downfield with precision and power, but he might toss the ball to a nearby teammate during warm-ups. When you toss something, you're often being a bit careless about where it lands, like when you toss your backpack in the corner or toss dirty clothes toward the laundry basket.

Toss also means to move or turn restlessly. Someone who can't sleep might toss and turn in bed all night, rolling from side to side. A boat tosses on rough waves, rocking back and forth.

As a noun, a toss is a light throw or flip. When you need to make a random choice between two options, you might do a coin toss: you flip it in the air and see whether it lands on heads or tails. This kind of coin toss is considered perfectly fair because neither side has an advantage.