| inappealable |
| incontestible |
| insusceptible(adjective, safe, unaffected, protected, resistant) |
| invincible(adjective, set, certain, unquestionable, indisputable) |
| ironclad(adjective, set, certain, unquestionable, indisputable) |
| irrebuttable(adjective, set, certain, unquestionable, indisputable) |
| irrefrangible(adjective, definite, precise, sure, decisive) |
| irrevocable(adjective, definite, precise, sure, absolute) |
| lawless |
| let off |
| litmus test(expression, adjective, definite, precise, sure) |
| no ifs and or buts(expression, adjective, idiom, sound, certain) |
| nof ifs ands or buts(expression, adjective, idiom, set, indisputable) |
| not affected(expression, adjective, safe, unaffected, resistant) |
| not liable(expression, adjective, safe, unaffected, resistant) |
| not subject(expression, adjective, safe, unaffected, resistant) |
| obvious(adjective, set, certain, definite, unquestionable) |
| odds-on(adjective, set, certain, unquestionable, indisputable) |
| open and shut(expression, adjective, idiom, sound, certain) |
| payoff |