Extra Mature Cheddar
Extra Mature Cheddar refers to 'old money' that has been in a family for a minimum of 6 years. If somebody's ancestors inherited the family fortune, they're classed as an extra mature cheddar family.
“How do all of his relatives own 6 Lamborghinis and 2 islands?”
“He's extra mature cheddar.”
“He's extra mature cheddar.”