|Cornish Wrestling in 2007, from Wikipedia (Public Domain image.|
"'To give one a Cornish Hug'
The Cornish are masters in the Art of wrestling. Their hug is a cunning close with their fellow combatants, the fruit whereof is his fare fall or foil at the least. It is figuratively applicable to the deceitful dealings of such, who secretly design their over-through whom they openly embrace."
[Although attributed to Cornwall this phrase - if he has the meaning correct - is a little derogatory. It could however be a prideful thing in an age where endurance and an instinct for survival at any cost where looked up to. I am only guessing here!]