Eccentric is a dealer in dogs (9)
I believe the answer is:
airedales
'dogs' is the definition.
(Airedale is an example)
'eccentric is a dealer' is the wordplay.
'eccentric' indicates anagramming the letters.
'is'+'a'+'dealer'='isadealer'
'isadealer' with letters rearranged gives 'AIREDALES'.
'in' acts as a link.
(Other definitions for airedales that I've seen before include "Terriers originally bred in Yorkshire" , "The dogs" .)