neither
Not one and not the other of two choices.
Neither means not one and not the other of two things. When you're offered chocolate or vanilla ice cream but don't want either flavor, you might say “I want neither.” When two friends are arguing and both seem wrong, you might think neither of them has a good point.
The word often pairs with nor to create a negative that works correctly in English. “Neither the book nor the movie was very good” means both disappointed you. “Neither rain nor snow stops the mail carrier” means the mail gets delivered regardless of the weather.
Neither usually works differently than none, which often refers to zero out of three or more options. If someone asks whether you want chocolate, vanilla, or strawberry ice cream, you'd say “none of those” rather than “neither.”
You can also use neither to agree with a negative statement. If your friend says “I don't like broccoli,” you might respond “Neither do I” or “Me neither,” meaning you share their opinion. The verb switches to match the new subject, so you can say “Neither does she” or “Neither would we.”