The term 'in-between space' can be summarized as a GAP or an area of emptiness between two objects. It is often used to describe the distance between two points, such as the space between two buildings or the space between two people. The term can also be used to describe a period of time in which nothing happens, such as a pause in a conversation or a break in a song. The crossword solution for this term is GAP, which is an appropriate description of the concept.