A mature cheddar head is someone who is very mature but acts really stubborn and stuck-up with it, quite snobby. They are mature in a really boring way with no sense of humour and take everything seriously.
'Sophie told me making fart noises is immature.'
'Don't worry, she's a mature cheddar head with no sense of humour.'
'Don't worry, she's a mature cheddar head with no sense of humour.'
by mousey1306 March 07, 2012
Mature cheddar is slang for "old money". If somebody inherited their fortune, they are classed as mature cheddar.
by C L G July 04, 2021
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.
by C L G July 04, 2021