Grenade
Definition 1 of 2
Pro Tip 1/3
Dangerous Object
A grenade is a weapon, so using it in similes implies something dangerous or harmful. His sudden resignation was a grenade in the company's stability.
Pro Tip 2/3
Immediate Action
Speaking about grenades usually means quick action is needed because of the immediate danger they present. Drop the grenade and run to safety!
Pro Tip 3/3
Not a Toy
Grenades are serious and deadly weapons; they should be spoken about with caution and respect. He learned about the severity of war when he saw a grenade explode.