| cool |
| expedient(free, informal, casual, impulsive, snap) |
| fake(adjective, free, casual, impulsive, spontaneous) |
| free(casual, impulsive, spontaneous, unprepared, impromptu) |
| from the hip(expression, adjective, idiom, impulsive, spontaneous) |
| hasty(adjective, impulsive) |
| immediate(free, informal, casual, impulsive, snap) |
| improvisatory(free, informal, casual, impulsive, snap) |
| informal(free, casual, impulsive, snap, spontaneous) |
| instantaneous(adjective, impulsive) |
| jamming(free, informal, casual, impulsive, snap) |
| jury-rigged |
| live |
| made-up(free, impulsive, spontaneous, impromptu, improvised) |
| off the hip(expression, idiom, offhand, impromptu, extemporaneous) |
| off the top of head(expression, idiom, free, informal, impromptu) |
| on-the-spot(free, informal, casual, impulsive, snap) |
| on impulse(expression, free, informal, casual, snap) |
| played by ear(expression, adjective, idiom, unqualified, unprepared) |
| prepared |