unsafe

1 involving potential loss or injury workers are forbidden from engaging in unsafe activities on company time Synonyms grave, grievous, hazardous, jeopardizing, menacing, parlous, perilous, risky, serious, threatening, unhealthy, dangerous, venturesomeRelated Words dicey, insecure, precarious, treacherous, uncertain; ultrahazardous; chance, haphazard, random; distressing, sickening, unpleasant; ugly, wicked; adverse, bad, baleful, baneful, deleterious, detrimental, evil, harmful, hurtful, ill, inimical, injurious, malignant, nasty, noxious, pernicious, pestilent; deadly, deathly, destructive, dire, fatal, fateful, fell, killer, lethal, mortal, murderousNear Antonyms advantageous, beneficial, good; ultrasafeAntonyms harmless, innocent, innocuous, nonhazardous, nonthreatening, safe, unthreatening

2 not paying or showing close attention especially for the purpose of avoiding trouble people who have a record of being unsafe drivers usually have to pay higher insurance premiums Synonyms heedless, incautious, mindless, unguarded, careless, unwaryRelated Words bold, impetuous, rash, reckless; inattentive, regardless; blithe, inconsiderate, thoughtless; absentminded, forgetful, unmindful; lax, neglectful, negligent, remiss, slipshod; imprudent, indiscreet, injudicious; inadvertent, unintentional, unplannedNear Antonyms attentive, chary, observant, vigilant, watchful; foresighted, forethoughtful, provident; calculating, scheming, shrewd; considerate, thoughtful; ultracareful, ultracautiousAntonyms alert, cautious, circumspect, gingerly, guarded, heedful, safe, wary