Honest; genuine; fair play.
There could hardly be a more Southern Hemisphere expression than 'fair dinkum'. The phrase, which is hardly used outside Australia, conjures up images of horny-handed farm hands with corks on their hats. A 'fair-dinkum Aussie' is indeed what the locals call someone who embodies the nation's values. So, where did the phrase originate? Alice Springs? Adelaide? No, Lincolnshire in England. That claim will take a little justifying, especially to readers down under, so here goes.
Firstly, let's get out of the way the folk-etymological tale that the phrase derives from the expression 'din gum', used by Chinese miners with the meaning ‘real gold’. My Chinese is less than perfect but I am told by Chinese speaking correspondents that 'din gum' (or 'zhen jin' in Mandarin) is a correct translation of 'real gold'. However, there's no evidence to link the phrase to China. There is, however, a mining connection in the phrase's background.
'Dinkum' is a slang term that appears to have grown up with two meanings, 'work' and 'fair play'. These may in fact be drawn from one original meaning, that is, 'honest toil'. The 'work' meaning of dinkum is found in print in documents from both Australia and the UK in the late 19th century, the earliest being in the classic Australian novel Robbery under Arms, published by Thomas Alexander Browne, using the pseudonym Rolf Boldrewood, in 1888. It also appears in Sidney Addy's Glossary of Words Used in the Neighbourhood of Sheffield, 1891:
‘I can stand plenty o' dincum.’ This word is used by colliers at Eckington. [Eckington is in East Derbyshire]
The 'honesty' or 'fair play' meaning is what people now mean by the phrase. The 'fair' was added to dinkum for emphasis, much in the same way that it was added to 'square' to make 'fair and square'. The 'fair play' meaning was known in England from at least 1882, as in this example from a report of a political meeting in Lincoln, reported in the Nottingham Evening Post, February 1882. The paper reports the opinions of Richard Hall, a local magistrate who was complaining about the unfair policies of the Gladstone government, which he believed favoured the wealthy:
In all of these things he thought there should be fair 'dinkum' to all classes of people.
'Fair dinkum' also appeared in Australia, in the Sydney newspaper The Bulletin, in 1894.
'Fair dinkum' was used by the colliers of the UK's East Midlands from the 1880s and by Australians from a few years later. In the late 19th century, in addition to the numerous criminals who were transported, many mineworkers migrated from England to Australia, taking their working language with them. Significantly as far as the derivation of this phrase is concerned, the direction of migration was very much one way and few migrants ever came back.