midsize
mid·size
or mid-size (mĭd′sīz′) or mid-sized (-sīz′)adj.
Of intermediate size. Used especially of motor vehicles, such as cars.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
midsize
(ˈmɪdˌsaɪz)adj
of an average or medium size; not particularly large nor particularly small
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014