Anti-gobbledegook campaigners are angry with coffee shops that flout the English language by offering customers “regular” sized drinks.

The Plain English Campaign, which crusades for clear language in public life, said regular was a meaningless term and has demanded that shops and cafes instead ask customers if they want “small, medium or large”.

A campaign spokeswoman said: “Almost every cafe now seems to ask if you want regular. They seem to use the word ‘regular’ when they really mean ‘small’ or ‘medium’. That’s not what ‘regular’ means – it’s irregular use of language.

“Large is the opposite of small, not the opposite of regular. The comedy duo was ‘Little and Large’ not ‘Regular and Large’ – and small, medium and large are all regular sizes.

“The opposite of regular is irregular. We didn’t learn about regular and large verbs at school. Perhaps we should start asking for an ‘irregular coffee’ – I wonder what that would be?”

She added: “We have three perfectly good words to describe drink sizes, which everyone understands. Cafes should stick to them and stop pointlessly offering this meaningless ‘regular’ size.”

Regular is one of the many words the coffee industry has brought into everyday use. In a market dominated by American multinationals, phrases like “do you want that to go?” or the use of “skinny” to describe a low-calorie drink have become de rigeur.

Coffee chain Starbucks has previously been criticised for using a bewildering lexicon to describe its drinks. Its customers can ask for a Venti Soy Caramel Macchiato – a large mug of foamed milk with espresso and vanilla – or a Chai Creme Frappuccino – a tea drink made with whipped cream and flavoured with spices.

The Plain English Campaign has previously roasted public bodies and multinational companies like Coca Cola for their use of rambling, bureaucratic waffle.