Definition of "atmo" in English

noun

1. (physics, dated) The standard atmospheric pressure used in certain physical measurements and calculations; conventionally, that pressure under which the barometer stands at 760 millimeters, at a temperature of 0° Centigrade, at the level of the sea, and in the latitude of Paris.

   • 1880? William Thomson, 1st Baron Kelvin, Heat under a constant pressure of one atmo

2. (colloquial) Clipping of atmosphere