sausage typically a chopped meat mixture stuffed into a tubular casing. The concept no doubt originated in antiquity, when it was desirable to find some way of preserving the blood and minor bits and pieces of a pig, rather than have to eat them immediately after the annual killing; see haggis; blood sausages. But the method has proved to be so adaptable and successful that sausages have come to take many forms, and questions of definition and classification are complex.
To take definition first, meat is not a defining characteristic. Fish sausages have been known since antiquity. Glamorgan sausages contain neither flesh nor fish nor fowl, but cheese and leeks. Nor is the familiar tubular shape essential; sausages may be spherical or ovoid or flattish; and tubular sausages may be straight or curved or even circular. Finally sausage casings, or ‘skins’ (see below), are unnecessary. If sausage mixtures are shaped into cohesive rolls, for example, these count as sausages because of their shape and composition. To exemplify two areas of flexibility in one product, Scotland has Lorne sausages, which are square (Glaswegian, ‘squerr’) in section and without a casing.