How to fix C++ error: expected unqualified-id

I'm getting this error on line 6:

error: expected unqualified-id before '{' token

I can't tell what's wrong.

#include <iostream>

using namespace std;

class WordGame;
{               // <== error is here on line 6
public:

    void setWord( string word )
    {
        theWord = word;
    }
    string getWord()
    {
        return theWord;
    }
    void displayWord()
    {
        cout << "Your word is " << getWord() << endl;
    }
private:
    string theWord;
}


int main()
{
    string aWord;
    WordGame theGame;
    cin >> aWord;
    theGame.setWord(aWord);
    theGame.displaymessage();

}

There should be no semicolon here:

class WordGame;

...but there should be one at the end of your class definition:

...
private:
    string theWord;
}; // <-- Semicolon should be at the end of your class definition

As a side note, consider passing strings in setWord() as const references to avoid excess copying. Also, in displayWord, consider making this a const function to follow const-correctness.

void setWord(const std::string& word) {
  theWord = word;
}

Get rid of the semicolon after WordGame.

You really should have discovered this problem when the class was a lot smaller. When you're writing code, you should be compiling about every time you add half a dozen lines.

Semicolon should be at the end of the class definition rather than after the name:

class WordGame
{
};