Tightly means firmly, closely, or securely, with little or no looseness or space. When you tie your shoelaces tightly, you pull them snug so they won't come undone while you run. When a lid fits tightly on a jar, no air can get in or out. When friends hug tightly, they squeeze each other close.

The word describes both physical closeness and secure connections. A tightly packed suitcase has every inch of space used, with clothes pressed together. A tightly knit community means people who stick together and support each other strongly. A tightly controlled experiment means scientists are careful to change only one variable at a time.

You can also shut your eyes tightly when you don't want to see something scary, or grip the handlebars tightly when riding your bike down a steep hill. The opposite is loosely: if you hold something too loosely, it might slip away.

Notice how tightly suggests both security and sometimes restriction. A tightly wrapped present stays protected, but a rule that's enforced too tightly might not allow for common sense exceptions.