while something else is happening or until something else happens.
You go back to school to learn a new trade and hope you can keep the family together in the meanwhile.
in the meanwhile
In the time before something else finishes or is supposed to happen. We need to wait for the movie to download. Let's get the popcorn ready in the meanwhile.
in the ˈmeantime/ˈmeanwhile
in the time between two things happening: In five minutes, there’s the news. In the meantime, here’s some music.The bus doesn’t leave until six o’clock. In the meantime we can go and have a coffee.I hope to go to medical school eventually. In the meanwhile, I’m going to study chemistry.