Sausage (sos-ij) – noun.
The word originates from the mid 15th century:  Middle English sau-sige, dialectal Old French sausiche, Late Latin salsi-cia,  neuter plural of salsi-cius  seasoned with salt, derivative of Latin salsus or salted.
“A lozenge of minced pork, beef, or other meats, often combined, together with various added ingredients and seasonings, usually stuffed into a tube-shaped animal intestine or synthetic casing and often made in links” Sausage making is a logical outcome of the philosophy of nose-to-tail consumption. Early humans made the first sausages by mincing all the otherwise useless bits and pieces of the animal and then stuffing them into the intestines or stomach of the beast before roasting.

Later generations were to refine and finesse this process by experimentation with salting, roasting, marinating and smoking the scraps of meat and offal  left over after the whole animal has been butchered and jointed.

The resultant mixture would then be chopped or minced and mixed with the blood before being stuffed into tubular casings, generally made from the cleaned stomach or intestines of the animal or animals concerned, and then cooked.
Haggis is a prime example of this!

The practice has developed many different ways in countless different countries around the world until today when sausages, puddings, and salami are among some of the oldest of prepared foods  known to man. Whether cooked and eaten immediately or dried to varying degrees, variations of the art of sausage making are innumerable though the best known sausage we have today in the UK is ‘the Banger’

The stomachs and intestines have largely been replaced by collagen, cellulose, or even plastic casings and the fillings are much more likely to be of fresh and untainted meat too.

Efforts to improve the flavour and quality of the sausage have continued over the centuries and thankfully some of the more questionable ingredients have fallen by the wayside until by the end of the nineteenth century the sausage was a much more refined product!

Since then, the meat to ‘other ingredients’ ratio has also been rationalised and regulated by various governments in order to improve the health of the populace as a whole! For the same reason the meat to fat ratio has also been regulated with fat being reduced to a maximum of 30-40%.

The meat may be from any animal, but traditionally is pork, beef, veal or more recently, venison, though nothing is really exempt.
Except that is for the war years! During both world wars, the meat content of sausages was cut due to inevitable meat rationing and the other ‘elements’ e.g. breadcrumbs and water increased to achieve the original weight. Because of the higher water content, the sausages were liable to burst in a hot frying pan, earning them the name bangers!  (This may also have led to the colloquial phrase ‘not a sausage’ coming to mean ‘nothing at all’)