"region of the earth's atmosphere above the stratosphere and below the thermosphere," 1950, from meso- "middle" + second element in atmosphere.
mesoderm
mesolithic
mesomorph
meson
Mesopotamia
mesosphere
mesothelioma
Mesozoic
mesquite
Mesropian
mess
)window.location='https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=byronic106@yahoo.com&lc=US&item_name=Donation+to +Help+Keep+Etymonline+Free+and+Open&no_note=0&cn=&curency_code=USD&bn=PP-DonationsBF:btn_donateCC_LG.gif:NonHosted'){kind=link}