| natural(adjective, calm, open, simple, plain) |
| involuntary(noun, adjective, reasonable, common, ordinary) |
| automatic(adjective, free, fake, natural, casual) |
| impulsive(noun, adjective, moving, simple, easy) |
| instinctive(noun, adjective, simple, easy, natural) |
| unpremeditated(noun, adjective, free, impulsive, planned) |
| unplanned(noun, adjective, free, fake, informal) |
| extemporaneous(noun, adjective, plain, impulsive, willing) |
| impromptu(adjective, adverb, free, plain, impulsive) |
| voluntary(adjective, feature, characteristic, free, deliberate) |
| innate(adjective, natural, instinctive, gut, automatic) |
| unprompted(adjective, plain, natural, thoughtless, impulsive) |
| instinctual(adjective, natural, unconscious, instinctive, automatic) |
| unforced(adjective, feature, characteristic, simple, regard) |
| unthinking(adjective, careless, natural, casual, emotional) |
| free(adjective, feature, characteristic, simple, fake) |
| offhand(noun, adjective, free, careless, casual) |
| inherent(adjective, reasonable, instinctive, automatic, intuitive) |
| mechanical(adjective, natural, routine, impulsive, instinctive) |
| gratuitous(adjective, feature, characteristic, free, deliberate) |