Lake formed by the Hoover Dam (4)
I believe the answer is:
mead
'lake formed by the hoover dam' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mead that I've seen before include "Honey-based alcoholic drink" , "Alcohol" , "Cooked joint" , "Drink made of fermented honey and water" , "Honey wine" .)