Definition of oversteer:
(n) :
The condition in which the rear wheels of a car don't follow the desired curve while cornering, the rear wheels losing a degree of traction and so skidding off the required line into a spin.
(v) :
to lose the control of one's vehicle in a corner due to rear wheels sliding and not following the front wheels
(v) :
to steer a vehicle too far in one direction.