Clunk (verb)

1. To make a heavy, dull sound when hit or moved.
2. To move or operate in a heavy, awkward, or mechanical way.

Origin:

Imitative origin, it is a sound that represents the action of a heavy thud or a hard hit. .

Examples:

1. The old car clunked as it drove down the road.
2. The suitcase clunked as he dragged it across the floor.
3. The gears clunked as he shifted into reverse.
4. The door clunked shut behind her.
5. The machine clunked as it started up.