Betting bad weather caused injury (6)
I believe the answer is:
sprain
'injury' is the definition.
(sprain is a kind of injury)
'betting bad weather' is the wordplay.
'betting' becomes 'sp'.
'bad weather' becomes 'rain' (rain is an example of bad weather).
'sp'+'rain'='SPRAIN'
'caused' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for sprain that I've seen before include "Pulled muscle" , "Slight muscle injury, eg to ankle" , "Wrench (ligaments)" , "Wrench (an ankle) 6)" , "Wrench, the ankle say" .)