A person who maintains or is an expert in aquariums; an alternative, less common spelling of 'aquarist.'
From 'aquari-' (relating to aquariums) plus '-ist' (one who practices or specializes in), though 'aquarist' with one 'i' became the standard form.
This spelling variant shows how English enthusiasts tried different ways to name their hobby—kind of like how 'fish tank expert' never quite had the same ring as the Latinized 'aquarist'!
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