1. Causing fear or anxiety by threatening great harm
   "a life-threatening disease"
   - dangerous, grave, grievous, serious, severe

See also: critical

• antineutron
• antinode
• antinoise
• antinomasia
• antinomian
• antinomianism
• antinomy
• antinuclear
• Antioch
• antiophthalmic factor
• antioxidant
• antiparallel
• antiparticle
• antipasto
• antipathetic
• antipathetical
• antipathy
• antipattern
• antiperistaltic
• antipernicious anemia factor
• antipersonnel
• antiperspirant
• antiphlogistic
• antiphon
• antiphonal