Lake on the California-Nevada border (5)
I believe the answer is:
tahoe
'lake on the california-nevada border' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tahoe that I've seen before include "Nevada/California lake" , "Mountain lake" , "Lake/desert resort on the California-Nevada border" , "the Nevada/California border area" , "US lake" .)