Get at article within container (6)
I believe the answer is:
attain
'get' is the definition.
(I know that attain is a more specific form of the action get)
'at article within container' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'within' is an insertion indicator.
'container' becomes 'tin' (tin is a kind of container).
'a' going into 'tin' is 'tain'.
'at'+'tain'='ATTAIN'
(Other definitions for attain that I've seen before include "Succeed in reaching, achieve" , "Fulfil" , "Achieve with effort" , "Reach objective, get there" , "Succeed in doing, get there" .)