| snap(adjective, free, casual, impulsive, prepared) |
| ad hoc(expression, adjective, free, casual, impulsive) |
| autoschediastic(adjective, free, fake, casual, impulsive) |
| by ear(expression, adjective, free, fake, casual) |
| casual(adjective, free, impulsive, spontaneous, unprepared) |
| expedient(adjective, free, casual, impulsive, spontaneous) |
| fake(adjective, free, casual, impulsive, spontaneous) |
| free(adjective, casual, impulsive, spontaneous, unprepared) |
| immediate(adjective, free, casual, impulsive, spontaneous) |
| improv(adjective, free, fake, casual, impulsive) |
| improvisational |
| improvisatory(adjective, free, fake, casual, impulsive) |
| improviso(adjective, free, fake, casual, impulsive) |
| impulsive |
| informal(adjective, free, casual, impulsive, spontaneous) |
| instinctive(adjective, natural, impromptu) |
| jamming(adjective, free, casual, impulsive, spontaneous) |
| jury-rigged |
| made-up(adjective, free, casual, impulsive, spontaneous) |
| natural |