a spear with three prongs
"The diver raised her trident, revealing its sharp three-pronged tip designed for securing slippery fish."
A three-pronged spear somewhat resembling a pitchfork.
"The ancient warrior brandished his trident, its three sharp prongs gleaming in the sunlight as he prepared to strike."
The nuclear weapon that is the nuclear deterrent of the United Kingdom
"After years of secret development, the UK government finally confirmed the deployment of its new Trident system to maintain strategic deterrence."