Docksider and Irwin rode away (9)
I believe the answer is:
stevedore
'docksider' is the definition.
I can't tell whether this defines the answer.
'irwin rode away' is the wordplay.
'irwin' becomes 'steve' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'away' indicates an anagram (letters move away from their original places).
'rode' is an anagram of 'dore'.
'steve'+'dore'='STEVEDORE'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for stevedore that I've seen before include "he'll have loads on board" , "One is employed at a dock to load and unload ships" , "Dock-worker loads and unloads ships" , "one working in docks" , "Hold worker" .)