(Greek > Latin: cheerful, gay, joyful, good spirits)
2. To cause to happen sooner; to hasten: Resting will often accelerate a person’s recovery from an illness.
When Darren will accelerate his car on the highway, the rush of air through the window will serve to exhilarate him; however, he needs to remember that excessive speed can also accelerate the process of getting a speeding ticket.
Stepping on the accelerator and moving at great speed is often an exhilarator to people; that is, until they get caught in a speed trap.
Exhilarate comes from the Greek element hilaros, "cheerful", which also gives us hilarious, "causing so much cheerfulness that people break out laughing.