Some of our best friends are soldiers (8)

I believe the answer is:

terriers

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'are soldiers' is the definition.
(soldiers in British Territorial Army)

I cannot understand how the remainder of the clue works.

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(Other definitions for terriers that I've seen before include "Part-time soldiers" , "eg Skye, Cairn and 18" , "Airedales, for example" , "Small short-bodied breeds of dogs" .)

I've seen this clue in the Evening Standard.

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