Dictionaries have changed their definition of the word “bully” following a campaign led by school pupils.

Pupils aged between 5 and 19  from across the country came together after a YouGov poll revealed that nearly three-quarters of British teenagers agreed that the definition of “bully” should be updated.

The previous definition in the Oxford English Dictionary was: “A person who uses strength or influence to harm or intimidate those who are weaker.”

But today it has been confirmed that Google, Collins, Dictionary.com, Oxford Dictionaries and Cambridge Dictionary have all changed their definition of a bully to: “A person who habitually seeks to harm or intimidate those who they perceive as vulnerable.”

The campaign #IAMNOTWEAK launched in November, and set out to harness the support of young people and social media to urge dictionary companies to remove the word “weak” from their definitions of “bully” or “bullying”.

It received widespread support from celebrities like Stranger Things actress Millie Bobby Brown, director and film producer Dustin Lance Black and American activist Monica Lewinsky.

In a video produced for the campaign by Sacred Heart Primary School, in Luton, Bedfordshire, working with the Diana Award charity, one Year 6 pupil says: “Pupils are bullied are not weak, people who are bullied are people unique, they are people who are smart, who are individual, who are different to the bullies.”

Alex Holmes, deputy CEO of The Diana Award, said: “Our groundbreaking, peer-led anti-bullying programme has trained over 27,000 young people across the UK and Ireland (and internationally) to act as anti-bullying ambassadors.

“A core part of our work is to educate young people that a bully is not inherently strong, and being a victim of bullying does not mean you are weak. By removing ‘weak’ from the definition we can instil confidence in those who have experienced or are still experiencing bullying, and help future generations better understand bullying behaviour.”