Dangerous, unsafe (5)
I believe the answer is:
risky
I believe this clue is a double definition.
'dangerous' is the first definition.
(similar in meaning)
'unsafe' is the second definition.
(similar in meaning)
(Other definitions for risky that I've seen before include "Involving a chance of danger" , "Having possibility of danger or loss" , "Potentially dangerous" , "too adventurous" , "taking a chance" .)