It is the first country to embrace the International Holocaust Remembrance Alliance
's (IHRA) explanation of the term, according to that organization. It aims to make it harder for culprits to get away with harassing and abusing Jews.
The wording can be adopted by the police, councils, universities and public bodies in order to "call out" anti-Semites, according to the British Prime Minister, Theresa May -- although it is not legally binding.
In a speech on Monday, May said: "It is unacceptable that there is anti-Semitism in this country. It is even worse that incidents are reportedly on the rise."
She explained the move means "there will be one definition of anti-Semitism -- in essence, language or behavior that displays hatred towards Jews because they are Jews -- and anyone guilty of that will be called out on it."
May made the speech at a private lunch for the Conservative Friends of Israel
attended by 800 guests.
The definition was agreed by the IHRA, an intergovernmental body made up of 31 member countries, in May this year. It states:
"Anti-Semitism is a certain perception of Jews, which may be expressed as hatred toward Jews. Rhetorical and physical manifestations of anti-Semitism are directed toward Jewish or non-Jewish individuals and/or their property, toward Jewish community institutions and religious facilities."
Member countries are mainly in Europe, but also include the United States, Canada, Israel and Argentina. Laura Robertson, communications officer for the IHRA, told CNN: "As far as we know, the UK is the first to adopt the definition."
"This is a positive step forward and we hope it will make an impact," said Dave Rich, deputy director of communications at the Community Service Trust (CST), an organization that monitors the Jewish community in the UK.
"Having a generally agreed definition of anti-Semitism that can be used by a range of different bodies, whether that's the police, the Crown Prosecution Service, student unions or social media companies -- all of whom have to address understanding what anti-Semitism is -- is useful."
Rise in hatred
According to a CST report
, there were 557 anti-Semitic incidents in the UK in the first six months of 2016, an 11% increase on the first six months of 2015.