unsafe

unsafe
un‧safe /ˌʌnˈseɪf◂/ adjective1. dangerous or likely to cause harm:
    The building is unsafe.
    water that’s unsafe to drink
2. likely to be harmed:
    Many people feel unsafe walking alone at night.
3. British English an unsafe judgment in a court of law is based on facts that may be wrong:
    an unsafe conviction
4. unsafe sex sex without using a condom
     

THESAURUS

   ▪ dangerous likely to cause death or serious harm, or cause something bad to happen: Snow and ice are making driving conditions very dangerous. | dangerous drugs | a dangerous criminal
   ▪ risky if something is risky, something bad could easily happen or you could easily make a mistake: Doctors said it was too risky to operate. | a risky situation
   ▪ hazardous /ˈhæzədəs $ -zər-/ especially written dangerous – used especially about substances, jobs, and journeys: hazardous waste | hazardous chemicals | hazardous occupations | The expedition was extremely hazardous.
   ▪ unsafe dangerous because someone is very likely to be hurt – used especially about places or conditions: The roads are unsafe for cyclists. | unsafe working conditions
   ▪ treacherous /ˈtretʃərəs/ formal literary places or conditions that are treacherous are very dangerous for anyone who is walking, driving, climbing etc in them: The snow turned to ice, making conditions treacherous for walkers. | the island’s treacherous coastline | With no lighting, the roads can be treacherous.
   ▪ perilous /ˈperələs, ˈperɪləs/ literary a perilous journey, situation etc is very dangerous: a perilous journey across the sea
   ▪ high-risk [only before noun] a high-risk job, situation, or behaviour is likely to be dangerous: Drug users need to know that sharing needles is high-risk behaviour.