Longman Dictionary of Contemporary English
Wiktionary
a. 1 (context horse racing cant English) of horses injected with something to make them run faster or change their temperament (19th-early 20th century) 2 (context US Navy slang English) drunk 3 (context of an engine, a motor vehicle or another device English) modified for higher performance (likely derived from the horse-racing term) 4 (context Rhode Island Massachusetts Connecticut slang English) excited
Usage examples of "souped-up".
There were thousands of them, blackening the sky, one-man sleds with souped-up engines for more speed, armed to the teeth with bolted-down energy guns and heavy projectile weapons, with long ribbons of bullets.
The craft ate up the distance, and Austin saw that it was a low- slung Cigarette boat like the souped-up models favored by Florida drug smugglers.
It was a souped-up Cushman with an extra set of twelve-volts, and headlights scavenged off a real Jeep.
Nikklin went off back to his brand-new four-wheel-drive truck with its souped-up Porsche under a neat tarp.
The Europeans turned it into a sport on their resort beaches in the early 1900s, and then it was only a matter of time before Southern California hot-rodders, racing their souped-up cars across the Mojave Desert's dry lakes, picked up on the idea, eventually holding organized racing events that drew participants from around the world who attained speeds close to 145 kilometers or 90 miles an hour.
The dicks had learned from eyewitnesses that they drove a souped-up white Ford pickup.
Using a controller, he used them to force me, marionettelike, onto a machine that looked like a souped-up imprinting unit.
Souped-up toys became engines of war as the airorses mounted the huge hulks, Vandys, Middle-guards, Rearguards, supply and support vessels, and blinked to assigned points, there to jockey into rehearsed formation, the formation of an Empire battle fleet.