reverser
nounUK /rɪˈvɜːsə/
US /rɪˈvɜːrsər/
A reverser is a person or thing that turns something around to the other way.
The reverser on the train helps it go backward.
OTHER MEANINGS
2. A device that makes a machine or vehicle go in the opposite direction.
The boat's reverser pushed the water the other way.
3. A person who changes a decision or rule back to what it was before.
The judge was a reverser of the old unfair rule.
4. A tool or machine that turns something inside out.
This reverser turns the jacket inside out in seconds.