Definition - using technology to gain an unfair advantage in an athletic event. Also known as technologic fraud.

A couple of excerpts describe this form of sophisticated cheating as well as I can:

• Bicycling.com
• "Rumors and serious accusations of racers using hidden motor systems have been around the sport since 2010, when Fabian Cancellara accelerated away from the field to win the Tour of Flanders, and Italian journalist and ex-pro Davide Cassani later demonstrated a system for RAI TV."
• Here is an example of a small motor that can be hidden inside the frame and give the rider "...200 watts of additional power to the crankshaft, but due to efficiency losses, actual power at the wheel is anywhere from 40 to 100 additional watts depending on the rider's own cadence. Burn time is 40 to 100 minutes..."
• Bikeradar.com
• One design is... "the Vivax Assist (formerly known as Gruber Assist) that is nearly completely hidden inside the frame. It's this concept (or something like it) that 'mechanical doping' alarmists claim is possibly being used at the highest levels of the sport."
• "In its current form, the Vivax Assist comprises a small cylindrical motor drive unit that slides down inside the frame's seat tube, tucked away from prying eyes, plus a small external battery. At the bottom of the motor unit is a small bevel gear that drives a retrofitted crank spindle. With a simple push of a handlebar-mounted button, the rider can summon up to 200 watts of extra pedaling power, essentially transforming an average cyclist into Chris Froome."
• "Claimed weight for the entire system is 1.8kg (3.97lb, complete, claimed) but even though that's already relatively svelte, such a system wouldn't be used in standard form."

• cyclingnews.com
  • But it appears things are moving quickly and the ..."use of electromagnetic wheels is the 'new frontier' of technological doping. A motor hidden in the seat tube is old stuff, almost artisan. It's been overtaken, it's a poor man's doping, Ghisalberti writes. The new frontier is far more technologically advanced and ten times as expensive. It's in the rear wheel: it costs 200,000 Euros, and there's a waiting list of six months. The first type uses a motor to turn the cranks; the second is electromagnetic." I'm sure we will hear more."