the Real McCoy

Meaning

The real thing - not a substitute.

Origin

This rivals 'the whole nine yards', 'okay' and 'the full monty' for pre-eminence in the 'I can explain that phrase' stakes. As usual, plausibility and frequent retelling are considered enough for absolute certainty. There are several people and things that the phrase has been applied to - which came first is uncertain.

1. McCoy is derived from Mackay, referring to Messrs. Mackay, Edinburgh, who made a brand of fine whisky from 1856 onwards and which that they promoted as 'the real Mackay' from 1870. 2. After Kid McCoy (Norman Selby,1873-1940), American welterweight boxing champion. The story goes, and there are various versions of it, that a drunk challenged Selby to prove that he was McCoy and not one of the many lesser boxers trading under the same name. After being knocked to the floor the drunk rose to admit that 'Yes, that's the real McCoy'. 3. The Canadian inventor Elijah McCoy made a successful machine for lubricating engines which spawned many copies all inferior to the original. He patented the design in 1872. 4. The phrase originates with a dispute between two branches of the Scots Mackay clan over who was their rightful leader. The head of one branch was Lord Reay, who came to be known as the Reay Mackay which migrated to 'the real McCoy'. 5. Joseph McCoy (1837-1915), became mayor of Abilene, Kansas as it developed into a sizeable town. He called himself 'the real McCoy'. 6. Bill McCoy was a US rumrunner during the prohibition years and his 'real' rum, imported from Canada, was compared favourably with poor quality local brews. 7. McCoy was a Pennsylvanian who supplied commercial nitro-glycerine to safecrackers who favoured it over their own home-made efforts. 8. McCoy is a corruption of Macao which was the source of a pure and sought after class of heroin. There are several other attempts at explanation going the rounds but they carry little conviction.