Intermediate: Adolescence is an awkward, in-between age. (adjective)
An intermediate: conservatives, radicals, and in-betweens. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "in-between" in a sentence
"Every building he designs has what he calls "in-between spaces," a reference to the spaces between buildings on farm compounds in rural Maryland."
"Gottman helped pioneer a rigorous means to capture what happened in the so-called in-between."
"In any case, since we are imagining that English borrows only the prefix concerning objects or life-forms of in-between status, and not the entire Swahili grammatical system of noun classifications, this detail need not worry us."