Another is a word used to describe an alternative. If your first bowling ball lands in the gutter, give it another try before you give up completely.
The word another comes from the Middle English term "an other," which is precisely what another is: some other alternative. It's used to refer to a different person, place or thing, or an additional person, place or thing. "Have another slice of pie," your mom might say. If there's another person in the room, or someone else, she might not be talking to you. Too bad.