noun [C usually singular] SLANG a small, cheap restaurant, especially one which sells a lot of fried food (from Cambridge Advanced Learner's Dictionary)
Greasy spoon is a colloquial term used in Britain and North America for archetypal working class eateries. Pioneered In the UK, these are generally technically called cafés (in England often abbreviated to "caff" or referred to as cafes, with no accent); in America such establishments are generally known as diners. The name "greasy spoon" is used to imply a less than rigorous approach to hygiene and dishwashing, and appears to date from 1925. Source: Wikipedia.

The stereotype in the UK is of poor quality greasy food — largely meatless sausages; salty, tasteless bacon; and weak, tepid, milky tea (or, in transport cafés, tea thick enough to float a lorry wheelnut, served just below the melting point of the mug). Further stereotyping would suggest that the customary reading material of the clientele is tabloid newspapers, most commonly The Sun or, in the case of roadside greasy spoons, the further downmarket Star or Sport. In practice, cafés vary widely; indeed some are excellent and take advantage of their minimal overheads by offering good, unpretentious food at quite remarkable value.

Like their British counterparts the typical American greasy spoon serves mainly fried or grilled food, for example: fried eggs, bacon, burgers, hot dogs, hash browns, waffles, pancakes, omelettes, deep fried chicken and sausages. These are often accompanied by baked beans, french fries, cole slaw, or toast. Coffee is ubiquitous, but often stereotyped as being hours old and strong from cooking down on a warmer. Alcoholic drinks are not usually sold.

Similar to their British and American counterparts the typical Canadian greasy spoon serves mainly fried or grilled food, for example: fried eggs, bacon, burgers, hot dogs, hash browns, waffles, pancakes, omelettes, deep fried chicken and sausages. The vast majority of a Canadian greasy spoon's business is during the morning hours.

In Hong Kong a greasy spoon is called a cha chaan teng (literal translation: "tea restaurant"). The menu and setting are somewhat similar to British greasy spoons, probably due to Hong Kong being a former British colony. Normally the menu will include traditional Chinese dishes including fried or boiled noodles, or a plate of fried rice, while the "Western" menu includes French toast, spaghetti bolognese, full English breakfast (albeit Sinicised), a pork chop with spaghetti, grilled chicken club, etc. These choices are usually accompanied by a triangular piece of toast and a choice of coffee, tea, Horlicks and Ovaltine (for children), or a Hong Kong speciality called yuanyang (a mixture of milk, coffee and tea). Most cheese-based dishes are not served in Hong Kong greasy spoons, due to Chinese tastes.