| chief(great, heavy, significant, substantial) |
| considerable(significant, substantial, valuable, vital) |
| critical(great, heavy, significant, substantial) |
| crucial(great, heavy, significant, substantial) |
| decisive(significant, substantial, valuable, vital) |
| determining(significant, substantial, valuable, vital) |
| earnest(significant, substantial, valuable, vital) |
| essential(significant, substantial, valuable, vital) |
| exceptional(great, heavy, significant, substantial) |
| exigent(significant, substantial, valuable, vital) |
| extensive(significant, substantial, valuable, vital) |
| far-reaching(important, significant, substantial, valuable) |
| grave(great, heavy, significant, substantial) |
| heavy(great, outstanding, substantial, valuable) |
| imperative(significant, substantial, valuable, vital) |
| importunate(significant, substantial, valuable, vital) |
| large(significant, substantial, valuable, vital) |
| marked(significant, substantial, valuable, vital) |
| material(significant, substantial, valuable, vital) |
| mattering much(expression, significant, substantial, valuable) |