| inborn(adjective, characteristic, start, reasonable, common) |
| innate(adjective, characteristic, start, reasonable, common) |
| inherent(adjective, characteristic, start, reasonable, common) |
| ingrained(adjective, start, natural, instinctive, be) |
| intrinsic(adjective, characteristic, start, natural, fixed) |
| natural(adjective, start, normal, everyday, instinctive) |
| native(adjective, start, natural, instinctive, be) |
| inbred(adjective, characteristic, start, natural, fixed) |
| instinctual(adjective, inside, instinctive, interior, automatic) |
| intuitive(adjective, natural, inside, instinctive, automatic) |
| habitual(adjective, inside, instinctive, interior, automatic) |
| hereditary(adjective, characteristic, natural, fixed, be) |
| constitutional(adjective, characteristic, start, natural, fixed) |
| intuitional(adjective, inside, instinctive, interior, automatic) |
| knee-jerk(adjective, inside, instinctive, interior, automatic) |
| rooted(adjective, inside, instinctive, interior, automatic) |
| second-nature(adjective, inside, instinctive, interior, automatic) |
| accustomed(adjective, inside, instinctive, interior, automatic) |
| indigenous(adjective, start, complete, reasonable, natural) |
| inherited(adjective, complete, natural, be, native) |