Question

That beeping sound indicates that the truck is backing up.‎

Accepted Answer

(idiomatichttps://en.wiktionary.org/wiki/Appendix:Glossary#idiomatic, intransitivehttps://en.wiktionary.org/wiki/Appendix:Glossary#intransitive) To move backwardshttps://en.wiktionary.org/wiki/backwards, especially for a vehicle to do so.

Sentence	That beeping sound indicates that the truck is backing up.‎
Definition	( idiomatic https://en.wiktionary.org/wiki/Appendix:Glossary#idiomatic , intransitive https://en.wiktionary.org/wiki/Appendix:Glossary#intransitive ) To move backwards https://en.wiktionary.org/wiki/backwards , especially for a vehicle to do so.

Beeping Sound Truck Backing Up.‎ Move Vehicle