Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

in law, a conviction is the verdict that results when a court of law finds a defendant guilty of a crime.
conviction

language death is when a language stops being used as a first language (also called mother language or native language) and as a second language, which it then becomes an extinct language.
language death

combinatorial optimization is a branch of discrete mathematics.

combinatorial optimization