Dizzee Rascal at Ketners Club, London, Braitain - 14 May 2009
'Some people think I'm bonkers/But I just think I'm free.' Photograph: Rex Features

Perhaps not since it ruled the school playgrounds of the 1980s has the word "bonkers" enjoyed such a moment in the sun. But in recent weeks the word has bounded back into common parlance, thanks to the Dizzee Rascal single of the same name.

Bonkers, which debuted at No 1 in the UK singles chart three weeks ago, was produced by Armand Van Helden, and its chorus runs: "Some people think I'm bonkers/But I just think I'm free." The word "bonkers" is repeatedly intoned in a voice that is belly-deep and robotic.

Bonkers is a British word that, according to Word Detective, the online etymological resource, first cropped up in the early 20th century, then meaning "light-headed, giddy" or "slightly drunk". The word evolved to mean insanity at some point after the second world war, but this is now the accepted usage.

Quite where and how "bonkers" originated is unknown, though many suspect it may well have been coined in the navy. Most likely it stems from the word "bonk", meaning "a blow to the head". Though Dizzee chooses to use the word on its own, bonkers often appears accompanied by intensifying words. "Depending on the severity of the affliction," notes Word Detective, "a person adjudged 'raving bonkers' or 'stark staring bonkers' is not someone you want to sit next to on the subway."

However the word is not without controversy. "Although 'bonkers' can be seen as a jovial term, it can be offensive when directed at someone in mental distress," says Alison Kerry at the mental health charity Mind. "And using it flippantly makes it look like it's OK to be routinely derogatory towards vulnerable people in our society. Widespread use of stigmatising terms only adds to our misunderstandings around mental health." Perhaps something to bear in mind, Mr Rascal.