Odds on wet weather causing injury (6)
I believe the answer is:
sprain
'injury' is the definition.
(sprain is a kind of injury)
'odds on wet weather' is the wordplay.
'odds' becomes 'sp' (betting abbreviation for starting price).
'on' means one lot of letters go next to another.
'wet weather' becomes 'rain' (I've seen this before).
'sp'+'rain'='SPRAIN'
'causing' acts as a link.
(Other definitions for sprain that I've seen before include "Wrench (limb)" , "Rick" , "Wrench or twist" , "Wrench, dislocate" , "Injure joint by wrenching it violently" .)