from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An automotive part that combines the transmission and the differential and is used on vehicles with front-wheel drive.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A single unit combining transmission gearbox, clutch, final drive, and differential are combined into a single unit connected directly to the driveshaft, used mostly in rear-engine cars.
trans(mission) + axle.(American Heritage® Dictionary of the English Language, Fourth Edition)
Blend of transmission and axle (Wiktionary)