| primitive(adjective, important, significant, original, essential) |
| primordial(adjective, important, significant, original, essential) |
| principal(adjective, important, significant, original, essential) |
| radical(adjective, base, important, significant, last) |
| required(adjective, important, essential, critical, basic) |
| requisite(adjective, important, significant, original, essential) |
| rudimentary(adjective, important, significant, fresh, original) |
| significant(adjective, important, original, essential, critical) |
| structural(adjective, important, significant, original, basic) |
| substratal(adjective, important, significant, fresh, original) |
| substrative(adjective, important, significant, original, essential) |
| supporting(adjective, important, significant, original, essential) |
| sustaining(adjective, important, significant, original, essential) |
| theoretical(adjective, important, significant, original, essential) |
| underived(adjective, important, significant, fresh, original) |
| underlined(adjective, important, essential, critical, basic) |
| underlying(adjective, base, important, significant, last) |
| urgent(adjective, important, essential, critical, basic) |
| vital(adjective, important, significant, original, essential) |
| WK(adjective, renowned, meritable, noted, highpowered) |