automatic reaction (noun) knee-jerk reaction: automatic response
Sinonime: at once, betimes, directly,
first, freshly, in a jiffy, in an instant, in no time, instantaneously,
instantly, newly, presto, primitively, promptly,
recently, right away, seasonably, soon, straightaway, summarily, thereon, thereupon,
timely, without delay
Antonime: late