The term has been used widely in the UK for many years when referring to the fast-food chain, but has not previously been officially adopted by McDonald's itself.
Other fast-food restaurant chains have also sought to promote abbreviated versions of their brand names, such as 'KFC' for Kentucky Fried Chicken and 'BK' for Burger King.
Earlier this year, Pizza Hut tried to promote truncated name 'The Hut' in its advertising campaigns.
This is not the first time has used slang to promote its restaurants.
In 2003, the chain unveiled its 'I'm lovin' it!' strapline, which was designed to take the brand in a fresh direction.
At the time, McDonald's said that the phrase would be the strategic 'glue' for upcoming global marketing and ad campaigns, which it wanted to be 'relevant, hip and energetic'. US pop singer Justin Timberlake was drafted in to promote the tag.
Last month, the fast-food chain celebrated the 35th anniversary of its arrival in the UK with a nostalgic campaign
that focused on some of its best-known menu items. The push, which uses the strapline 'There's a McDonald's for everyone', shows the range of people who visit the restaurants.