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.
Almost a quarter (24%) of these related to hate expressed on social media and eight in ten of the total took place in the cities of London and Manchester.
The CST said there was no obvious single cause for the year-on-year rise and it did not record a significant increase in incidents immediately following the EU referendum vote
on 23 June 2016, as was seen with other forms of hate crime.
The longer term trend shows that CST has recorded a sustained high level of hatred expressed towards Jews since July and August 2014 when reactions in the UK
to that summer's conflict in Israel and Gaza led to record levels of incidents.
May used her speech to criticize the opposition Labour party for failing clamp down on anti-Semitism in its ranks.
"It is disgusting that these twisted views are being found in British politics," she said. "Of course, I am talking mainly about the Labour Party and their hard-left allies."
May delivered her speech on the same day that British Home Secretary Amber Rudd announced that the neo-Nazi group National Action group will be banned under anti-terror laws from Friday.
The move means that supporting or being a member of the organization will be a criminal offense, carrying a potential 10-year prison sentence.
"National Action is a racist, anti-Semitic and homophobic organization which stirs up hatred, glorifies violence and promotes a vile ideology, and I will not stand for it. It has absolutely no place in a Britain that works for everyone," said Rudd.
In a statement sent to CNN, a spokesperson for National Action denied any instigation of violence.