| inactive(adjective, dull, quiet, flat, slow) |
| indifferent(adjective, dull, quiet, hard, flat) |
| indurated(adjective, hard, unfeeling, unsympathetic, established) |
| inert(adjective, dull, quiet, flat, slow) |
| informal(adjective, plain, common, ordinary, usual) |
| instant(present, modern, prevailing, existing, ongoing) |
| instructed(familiar, sophisticated, knowledgeable, skilled, competent) |
| irreverent(adjective, hard, unfeeling, unsympathetic, prepared) |
| jejune |
| knowing(plain, common, familiar, knowledgeable, skilled) |
| knowing the score(expression, idiom, familiar, sophisticated, knowledgeable) |
| knowledgeable(familiar, skilled, qualified, informed) |
| languid(adjective, dull, quiet, flat, slow) |
| leading-edge(present, modern, general, prevailing, existing) |
| long-established |
| mainstream(common, ordinary, natural, regular, commonplace) |
| matter-of-course(common, ordinary, natural, usual, regular) |
| mature(familiar, sophisticated, knowledgeable, skilled, competent) |
| matured(familiar, sophisticated, knowledgeable, skilled, competent) |
| methodical(adjective, ordinary, usual, regular) |