| principal(adjective, significant, essential, basic, vital) |
| substantial(adjective, significant, importance, powerful, characteristic) |
| foremost(adjective, characteristic, significant, essential, main) |
| material(adjective, significant, substantial, importance, characteristic) |
| great(adjective, excellent, exceptional, valuable, characteristic) |
| urgent(adjective, characteristic, serious, critical, vital) |
| chief(adjective, great, significant, essential, basic) |
| signal(adjective, outstanding, characteristic, great, extraordinary) |
| pivotal(adjective, characteristic, importance, significant, significance) |
| powerful(adjective, strong, effective, influential, characteristic) |
| big(adjective, substantial, famous, significant, valuable) |
| key(adjective, importance, characteristic, valuable, main) |
| main(adjective, significant, essential, basic, characteristic) |
| necessary(adjective, significant, essential, critical, basic) |
| remarkable(adjective, notable, importance, outstanding, great) |
| considerable(adjective, significant, substantial, large, ample) |
| impressive(adjective, bad, strong, great, excellent) |
| central(adjective, significant, essential, basic, vital) |
| illustrious(adjective, famous, prominent, eminent, great) |
| primary(adjective, significant, substantial, essential, basic) |