Run - I'm scared opening of Surströmming will produce unpleasant smells (5)
I believe the answer is:
reeks
'smells' is the definition.
(reek is a kind of smell)
'run i'm scared opening of' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'i'm' becomes 'eek' (I can't justify this - if you can you should believe this answer much more).
'opening of' suggests taking the first letters.
The initial letter of 'scared' is 's'.
'r'+'eek'+'s'='REEKS'
'surstromming will produce unpleasant' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for reeks that I've seen before include "Gives off a strong unpleasant smell" , "Macgillycuddy's - -" , "Stinks to high heaven" , "offensive odours" , "Is humming" .)