Valid means logically sound, legally acceptable, or genuinely true. When your teacher says you've made a valid point in a class discussion, she means your reasoning makes sense and deserves consideration. A valid argument is one built on solid logic and facts, not wishful thinking or faulty reasoning.

The word appears in different contexts with slightly different flavors. A bus ticket is valid if it hasn't expired and can still be used. A passport is valid if it's current and officially recognized. In these cases, valid means legitimate or acceptable according to the rules.

In everyday conversation, people often say “that's valid” to acknowledge someone's feelings or perspective, even if they don't fully agree. If your friend is nervous about trying out for the school play, you might say “your concern is valid” because those feelings make sense given the situation.

The opposite is invalid. An invalid excuse doesn't hold up under scrutiny, like claiming your dog ate your homework when everyone knows you don't have a dog. An invalid driver's license can't legally be used anymore.

When you're building an argument or making a case for something, aim for validity by ensuring your reasoning actually supports your conclusion. A valid argument isn't necessarily true, but it is logically consistent and worth taking seriously.