1) Layer 
The mesosphere (ɪər; from Greek mesos `middle` and sphaira `ball`) is the layer of the Earth`s atmosphere that is directly above the stratopause and directly below the mesopause. In the mesosphere temperature decreases with increasing height. The upper boundary of the mesosphere is the mesopause, which can be the coldest naturally occurring...
The region of the atmosphere between about 50 km and 80-85 km, extending from the top of the stratosphere to the upper temperature minimum. It is characterized by a broad temperature maximum (near 0 
The layer of the Earth's atmosphere above the stratosphere.
A division of the Earth's atmosphere extending from altitudes ranging 18-30 miles to 48-55 miles.
region of the upper atmosphere between about 50 and 80 km (30 and 50 miles) above the surface of the Earth. The base of the mesosphere is defined as ... [4 related articles]
The part of Earth`s atmosphere immediately above the stratosphere, where the temperature drops from about 270 K to 180 K. It lies between the stratopause and the mesopause and overlaps the lower part of the ionosphere.
that part of the Earth's atmosphere located above the stratosphere and in which the temperature decreases with increasing height; this part of the atmosphere extends to a height of around 85 km, at which height the temperature reaches a minimum value
Region of the atmosphere between approximately 50 and 85 km. 
A layer of the atmosphere separated by the ionosphere above and the stratosphere below extending from about 50km-80km above the Earth's surface. The air temperature in mesosphere decreases with height.
Atmospheric layer found between the stratosphere and the thermosphere. Usually located at an average altitude of 50 to 80 kilometers above the Earth's surface. Air temperature within the mesosphere decreases with increasing altitude.
atmospheric layer above the stratosphere (50-85 km altitude).
[n] - the atmospheric layer between the stratosphere and the thermosphere
the region of the atmosphere between about 50 kilometers (31 miles) and 80-85 kilometers (50-53 miles), extending from the top of the stratosphere to the upper temperature minimum; it is characterized by a broad temperature maximum (near 0 degrees Celsius) at its base, from which the temperature decreases to a minimum (about -90 degrees Celsius) at...
The layer of the atmosphere lying between 50 - 100 km altitude. More Information.
noun the atmospheric layer between the stratosphere and the thermosphere
Layer in the Earth's atmosphere above the stratosphere and below the thermosphere. It lies between about 50 km/31 mi and 80 km/50 mi above the ground
A zone in the Earth between 400 and 670 km below the surface separating the upper mantle from the lower mantle.