1 general:: Phrase(s): in between located in the middle of two things, states, or possibilities. • The bath water is not hot or cold. It’s in between. • A sandwich consists of two slices of bread with some other food in between.
McGrawhill's American Idioms And Phrasal Verbs
2 general:: In an intermediate situation, as in My roommates disagreed and I was caught in between. [Late 1500s]
American Heritage Idioms