1. gigaton; gigatons.
2. Also called GT car, grand touring car, grand touring. Auto.
a. an automobile in the style of a coupe, usually seating two but occasionally four, and designed for comfort and high speed.
b. a high-speed, two-door model of a four-door sedan.
3. (in prescriptions) a drop.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.