Forcemeat is far less intimidating than it sounds; it’s simply a chef’s term used to refer to ground or pureed poultry, meat, seafood, or (rarely) vegetables used to stuff something else.  Most often it refers to meat blended with fat and seasonings to make a smooth mousse-like mixture that’s used as a filling (you may occasionally see chefs on TV poach forcemeat wrapped in plastic wrap to create traditional quenelles). 

Though the term evokes haute cuisine, the finished product needn’t be exotic: technically sausages and raviolis are both filled with forcemeat.