A person or thing that ameliorates; something that makes conditions better or brings improvement.
From 'ameliorate' plus the agent suffix '-or' (one who does something). This noun form designates either an entity or person responsible for improvement.
An ameliorator could be a person (like a reformer), a policy, or even a technology—anything that intentionally makes things better. It's a formal word that positions whatever it describes as having genuine improving power.
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