A heavily armored battleship of the early 20th century type, built around big-gun firepower. By extension, anything formidable through sheer mass and menace. This spelling is a less common variant of dreadnought.

Variant spelling of dreadnought, originally “one who fears nothing,” from dread + nought “nothing.” The famous battleship name turned a boast into a category, and the category into a symbol of modern power.