Sturgeon eggs (7)
'sturgeon eggs' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for roe that I've seen before include "shy animal" , "Food from fish" , "Swift runner" , "Mass of fish's eggs" , "Mass of fish eggs" .)
(Other definitions for caviare that I've seen before include "Roe as delicacy" , "Sturgeon's roe" , "Avarice (anag)" , "Expensive delicacy" , "Salted roe" .)