class 간의 변수 공유에 대해서 질문 입니다...

///thread.h////
class Thread : QThread
{
    public:
      static int cnt;     

    private:
};
int Thread::cnt;

////trans.h////
class Trans : public Dialog
{
    public:

    private:
};


/////thread.cpp/////
void Thread::run()
{
   cnt++;
}


/////trans.cpp/////
void Trans::start()
{
   
} 

위의 코드와 같이 static으로 정의를 했습니다...

그리고 컴파일 하니 다음과 같은 에러가 났습니다...

thread.o(.bss+0x4):/home/eunsu/serial/sensor/threads/thread.cpp:7: multiple definition of `Thread::cnt'
main.o(.bss+0x0):/home/eunsu/serial/sensor/threads/main.cpp:6: first defined here
threadform.o(.bss+0x0):/home/eunsu/serial/sensor/threads/threadform.cpp:9: multiple definition of `Thread::cnt'
main.o(.bss+0x0): first defined here
moc_threadform.o(.bss+0x0):/home/eunsu/serial/sensor/threads/moc_threadform.cpp:20: multiple definition of `Thread::cnt'
main.o(.bss+0x0): first defined here
collect2: ld returned 1 exit status
make: *** [threads] 오류 1

에러가 왜 생기는지..... 다시 한번 답변 부탁 드릴께요...