Get double (5)
I believe the answer is:
fetch
I believe this clue is a double definition.
'get' is the first definition.
('fetch' can be a synonym of 'get')
'double' is the second definition.
(thesaurus)
(Other definitions for fetch that I've seen before include "Collect" , "Go and bring back" , "Go and get back, like dog with stick" , "Sell for" , "double" .)