The lexicographers at the Oxford English Dictionary must have been worried when they were confronted by a group of angry bikers.
According to the OED definition of the breed, they turn up in gangs with 'long hair' and 'dirty denims'.
And Britain's two most famous bikers, TV cooks David Myers and Simon King (see below) are so long-haired they frequently need ponytails.
However, the two-wheeled community has become fed up with the stereotype being perpetuated by the dictionary entry, which fell somewhere between the words 'bijou' and 'bikini'.
They reasoned that the likes of Prince William, David Beckham and George Clooney also ride motorcycles and they could hardly be described as shaggy and unkempt.
In fact, a survey had shown that only 9 per cent of male bikers have long hair.
Faced with such evidence, the Oxford University Press, which publishes the OED, has decided to alter its definition.
The online version previously defined a biker as: 'A motorcyclist, especially one who is a member of a gang: a long-haired biker in dirty denims.'
It now reads: 'A motorcyclist, especially one who is a member of a gang or group: a biker was involved in a collision with a car.'
Almost three-quarters of 524 bikers polled over the old definition found it inaccurate. One in five were 'outraged and offended' by it.
Furthermore, 65 per cent said they spent most of their time riding alone - and were not in a gang.
The study, by insurance firm Bennetts, found today's biker is most likely to be over 35, middle class, working in IT or telecoms and likely to ride a Honda. When the term 'biker' came into common usage 50 years ago, it often described gangs of leather-clad troublemakers.
Hannah Squirrell, from Bennetts, said: 'In the early 60s, biker was a relatively new term which provoked fear among many, partly due to their image portrayed in the media.
'Fortunately, since then, bikers have grown away from the cliched stereotype and now encompass all sectors of society.'
OUP spokesman Nicola Burton said: 'This change has been made to reflect a shift in use of the word "biker". Our research suggests biker is now more closely aligned with "motorcyclist" than words such as "Hell's Angel".'
Myers and King could not be contacted yesterday but a spokesman said: 'They will be amused by this.'
* David Myers and Simon King are from the Hairy Bikers cooking show on Choice TV.