n. A storm consisting of thunder and lightning produced by a cumulonimbus, usually accompanied with rain or hail. A more severe thunderstorm can cause mesocyclones.
the GNU version of the Collaborative International Dictionary of English
n. A storm accompanied with lightning and thunder.
The Century Dictionary and Cyclopedia
n. A storm accompanied by lightning and thunder, occurring when the atmosphere is in a state of unstable equilibrium, and has a high relative humidity.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a storm resulting from strong rising air currents; heavy rain or hail along with thunder and lightning
Word Usage
"So after lighting the storm lanterns for the inevitable collapse of the power grid, I get to enjoy the spectacle of the thunderstorm from the dry comfort of my front porch."