1. Exceedingly harmful
   - deadly, pernicious, pestilent 
2. Deadly or sinister
   - baleful

See also: maleficent, noxious

• black-coated
• black-crowned night heron
• black-eye bean
• black-eyed bean
• black-eyed pea
• black-eyed Susan
• black-eyed Susan vine
• black-footed albatross
• black-footed ferret
• black-fronted bush shrike
• black-gray
• black-grey
• black-haired
• black-headed snake
• black-legged tick
• black-marked
• black-market
• black-necked cobra
• black-necked grebe
• black-necked stilt
• black-necked stork
• black-seeded
• black-stem spleenwort
• black-stemmed spleenwort
• black-tailed deer