Complex sentence: The word "amulet" comes from the Latin "amulētum"; the earliest extant use of the term is in Pliny's "Natural History", meaning "an object that protects a person from trouble".
Split into simpler sentences: The word "amulet" comes from the Latin word "amulētum". The earliest extant use of that term is in Pliny's "Natural History", in which it means "an object that protects a person from trouble".