Master switch for the current (6)

I believe the answer is:

stream

'the current' is the definition.
('stream' can be a synonym of 'current')

'master switch' is the wordplay.
'switch' is an anagram indicator.
'master' anagrammed gives 'STREAM'.

'for' is the link.

(Other definitions for stream that I've seen before include "Small narrow flow" , "group of schoolchildren" , "One small river" , "Natural body of running water" , "Constant flow of liquid" .)

I've seen this clue in The Guardian, the Evening Standard, The Globe and Mail, The Irish News and The Irish Independent.

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