| intimate(adjective, simple, easy, plain, modest) |
| irresistible(adjective, simple, natural, casual, impulsive) |
| jamming(free, casual, impulsive, spontaneous, unprepared) |
| jury-rig |
| jury-rigged |
| laid back(expression, adjective, simple, straightforward, casual) |
| lick |
| loose(adjective, simple, easy, plain, relaxed) |
| mixed(adjective, simple, easy, plain, straightforward) |
| motley(adjective, simple, easy, plain, straightforward) |
| natural(adjective, simple, straightforward, casual, impulsive) |
| off hand(expression, idiom) |
| off the top of head(expression, adverb, free, impromptu, unrehearsed) |
| off top of head(expression, adjective, idiom, adverb, simple) |
| on-the-spot(free, casual, impulsive, spontaneous, unprepared) |
| on impulse(expression, free, casual, impulsive, unrehearsed) |
| open(adjective, simple, easy, plain, straightforward) |
| ordinary(adjective, simple, easy, plain, straightforward) |
| per saltum(expression, idiom, instantaneity) |
| random(chance, unplanned, unpremeditated) |