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

See also: critical

• inorganic chemistry
• inorganic compound
• inorganic phosphate
• inorganically
• inosculate
• inosculation
• inosine
• inositol
• inpatient
• inpour
• inpouring
• input
• input data
• input device
• input file
• input program
• input routine
• input signal
• inquest
• inquietude
• inquire
• inquirer
• inquiring
• inquiringly
• inquiry