Annihilationist, meaning a person or doctrine advocating for the complete destruction or obliteration of something, can be expressed in different ways using synonyms. Such terms include eraser, annihilator, obliterator, extirpator, and decimator. Other possibilities include the words destructionist, exterminator, and eradicator, which convey the same meaning of wanting to completely eliminate or annihilate something. The use of these synonyms can, in certain contexts, help clarify the intended meaning of the writer or speaker. However, it is important to note that they may not always be interchangeable with annihilationist, as different words may carry varying degrees of emphasis and tone.