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.

regent's canal is a canal in england.
regent's canal

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

a shore or shoreline is the land at the edge of a large body of water, such as an ocean or river.

shore