It's the end of the road, stranger, when you shake so! (6)
I believe the answer is:
dodder
'you shake so' is the definition.
I can't tell whether this definition defines the answer.
'it's the end of the road stranger' is the wordplay.
'it's the end of' indicates one should take the final letters.
'stranger' becomes 'odder' (I've seen this before).
The final letter of 'road' is 'd'.
'd'+'odder'='DODDER'
'when' is the link.
Can you help me to learn more?
(Other definitions for dodder that I've seen before include "Walk unsteadily along the Dublin river?" , "go falteringly" , "Be decrepit in the Dublin river" , "Be slow and unsteady" , "Totter into the Dublin river" .)