Broadcast by possible porter’s best friend? (8)

I believe the answer is:

airedale

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'best friend?' is the definition.
(I've seen this before)

'broadcast by possible porter's' is the wordplay.
'broadcast' becomes 'aired' (synonyms).
'by' says to put letters next to each other.
'possible porter' becomes 'ale' (I've seen this in other clues. I am not sure about the 'possible' bit.).
'aired'+'ale'='AIREDALE'

Can you help me to learn more?

(Other definitions for airedale that I've seen before include "Large breed of terrier" , "River valley; rough-coated terrier" , "Thematic type [DOG]" , "Terrier - Yorkshire area" , "Dog from Yorkshire" .)

I've seen this clue in The Times.

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