Definition of explosivity in US English:

explosivity

noun

  • 1The property of being explosive; the degree to which something is explosive.

  • 2Volcanic activity characterized by the forceful ejection of pyroclastic material; the magnitude of such activity during an eruption or phase of an eruption; the property of erupting in this way.

Origin

Early 20th century; earliest use found in Journal of the American Chemical Society. From explosive + -ity, in sense 1 after German Explosivität.