The term 'ceased to exist' can be expressed in two words: 'died' (4 letters) and 'perished' (8 letters). Both words refer to the same concept, that of ceasing to exist, but they have slightly different connotations. 'Died' is a more general term that can refer to any living thing, while 'perished' implies a more sudden or violent death. Both terms are used to describe the end of a life, whether it be human, animal, or plant.