One islet or eight, we hear (4)
I believe the answer is:
eyot
'one islet' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for eyot that I've seen before include "Islet found in a river, (especially in England)" , "isle" , "There's one at Chiswick" , "Small river island" , "Fawlty Towers waiter" .)