Chancy (4)
I believe the answer is:
iffy
'chancy' is the definition.
(I know that chancy can be written as iffy)
This is all the clue.
(Other definitions for iffy that I've seen before include "Colloquially uncertain or doubtful" , "Doubtful (colloq.)" , "Not to be trusted" , "Problematic" , "Full of uncertainty" .)