parking meter

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A device that registers the amount of time purchased for the parking of a motor vehicle, at the expiration of which the driver is liable for a fine.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A device, located by a parking space, that collects payment in exchange for the right to park a vehicle for a specified time.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a coin-operated timer located next to a parking space; depositing money into it entitles you to park your car there for a specified length of time