'aquarium-related' originates from Modern English as a compound of 'aquarium' and 'related'. 'aquarium' ultimately comes from Latin 'aquarium', where 'aqua' meant 'water'; 'related' comes from Latin 'relatus', the past participle of 'referre', where 're-' meant 'back' and 'ferre' meant 'to carry'.

'aquarium' entered English via Modern Latin (and scientific/vernacular use) meaning 'a place for water' or 'a container for water'; 'related' entered English through Old French and Latin past participles into Middle English before becoming the Modern English adjective 'related'. The compound 'aquarium-related' is a straightforward modern English formation combining the two.

Initially 'aquarium' referred specifically to a container or place for water (and later for keeping aquatic life); combined as 'aquarium-related' it now specifically means 'having a connection to aquariums or aquarium-keeping'.