A person or thing that causes desolation; one who abandons, destroys, or leaves something empty and sad.
From 'desolate' (verb) plus the agent noun suffix '-er'. This creates a noun for someone or something that performs the action of desolating.
Unlike 'desolate' which is usually used passively ('the landscape became desolate'), 'desolater' puts focus on an active agent—someone or something deliberately causing emptiness and sadness.
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