Fish tanks (7)
![Ross](/clue/static/ross-mug.min.png)
'fish tanks' is the definition.
(plural of aquarium)
This is the entire clue.
(Other definitions for aquaria that I've seen before include "display tanks" , "Tanks or buildings for fish" , "Transparent fish tanks" .)
(Another definition for aquariums that I've seen is " Tanks or bowls for fish".)