Run on skis involved hazards (5)
I believe the answer is:
risks
'hazards' is the definition.
('risk' can be a synonym of 'hazard')
'run on skis involved' is the wordplay.
'run' becomes 'r' (cricket abbreviation**).
'on' is an insertion indicator.
'involved' indicates anagramming the letters (involved can mean confusing or complex).
'skis' anagrammed gives 'isks'.
'r' placed inside 'isks' is 'RISKS'.
(Other definitions for risks that I've seen before include "Sources of dangers" , "Perils" , "Chances" , "Hazards, dangers" , "Puts in jeopardy" .)