This is the definition of Safeguarding as written in the Care Act 2014:
“Adult safeguarding” is working with adults with care and support needs to keep them safe from abuse or neglect. It is an important part of what many public services do, and a key responsibility of local authorities.
Safeguarding is aimed at people with care and support needs who may be in vulnerable circumstances and at risk of abuse or neglect. In these cases, local services must work together to spot those at risk and take steps to protect them. (Source: Factsheet 7 – Protecting adults from abuse or neglect. You can view the complete version here.)
Below are links for further information on safeguarding adults from the Care Quality Commission and Social Care Institute for Excellence (SCIE) including a YouTube clip to explain what Safeguarding is: