Wearied by anxieties, oarsman turns up in jail (8)
I believe the answer is:
careworn
'wearied by anxieties' is the definition.
'oarsman turns up in jail' is the wordplay.
'oarsman' becomes 'rower' ('rower' can be a synonym of 'oarsman').
'turns up' says the letters should be written backwards.
'in' indicates putting letters inside.
'jail' becomes 'can' (the can is American slang for prison).
'rower' backwards is 'rewor'.
'rewor' going inside 'can' is 'CAREWORN'.
(Other definitions for careworn that I've seen before include "stressed" , "worn-out" , "Showing signs of stress and worry" , "Tired through worry" , "Haggard, drawn" .)