| acute(adjective, significant, serious, vital, grave) |
| all-important |
| climacteric(adjective, significant, serious, vital, grave) |
| conclusive(adjective, significant, serious, vital, grave) |
| consequential(adjective, significant, serious, vital, grave) |
| crucial(adjective, significant, serious, vital, grave) |
| dangerous(adjective, significant, serious, vital, grave) |
| deciding(adjective, significant, serious, vital, grave) |
| decisive(adjective, significant, serious, vital, grave) |
| desperate(adjective, significant, serious, vital, grave) |
| determinative(adjective, significant, serious, vital, grave) |
| dire(adjective, significant, serious, vital, grave) |
| exceptive(adjective, significant, serious, vital, grave) |
| grave(adjective, significant, serious, vital, dangerous) |
| hairy(adjective, significant, serious, vital, grave) |
| hazardous(adjective, significant, serious, vital, grave) |
| high-priority(adjective, significant, serious, vital, grave) |
| integral(adjective, significant, serious, vital, grave) |
| momentous(adjective, significant, serious, vital, grave) |
| perilous(adjective, significant, serious, vital, grave) |