Cindy D. answered 01/05/16
Tutor
New to Wyzant
Experienced Elementary Teacher
Meantime and Meanwhile are synonyms. They mean approximately the same thing.
Meantime is used most often in my experience when a person is explaining what they will be doing between set activities or while someone else is completing an activity.
For example Diner is cooking. Mark in the meantime please set the table.
Meanwhile is more often used to describe events taking place at the same time but in different places.
Tony was fixing diner at home, meanwhile Mary was reading a book.