Aid means help or assistance given to someone who needs it. When you aid someone, you're doing something that makes their situation better or easier. A teacher might aid a struggling student by explaining a concept in a different way. A friend might aid you in cleaning up after a party. Countries send aid to regions hit by natural disasters, providing food, water, and medical supplies.

The word can be used as both a verb and a noun. You can aid someone (the action of helping), or you can provide aid (the help itself). A first aid kit contains supplies that aid injured people. A hearing aid helps people hear better.

Related words include aide (spelled differently), which means a person whose job is to assist someone, like a teacher's aide who helps in the classroom. There's also unaided, meaning without help: if you solve a difficult puzzle unaided, you figured it out entirely on your own.

Aid implies that someone genuinely needs assistance and that the help being offered is meaningful or necessary. When someone comes to your aid, they're stepping in when you really need them.