Megacannon

The prisoners—the President, the First Lady, and their son, nine-year-old Billy—their hands tied securely behind their backs, were marched from the ship and across the floor of the canyon to the base of an enormous megacannon.

Source: wiktionary

“Look,” he says, “I’m a razor from the ship’s bridge crew. The Rain brought down the zone and then hosed down the fleet with that DE megacannon outside—"

Source: wiktionary

All of which leads us back to Captain Stockton’s decision to ignore ship-builder Ericsson’s warnings about the megacannon Peacemaker that killed Secretary Upshur and his nonconfrontational ways and gave us the volatile Secretary Calhoun, who set the boiler to going with threats and rumblings of secession from the Southland.

Source: wiktionary

When they hit cruisers, they use hangar spam to mow down corvettes and bastions. When battleships are researched? Megacannons with proton and neutron launchers everywhere.

Source: wiktionary