Measurement of flow obstructed, except for border (6)
I believe the answer is:
ampere
'border' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ampere that I've seen before include "Current measure" , "scientist" , "Unit measured by 17 across" , "Unit of electrical current" , "Unit of currency" .)