即座|そくざsokuza[1]atamadaka (head-high)

1. no-adjectiveimmediate; right there on the spot; impromptu; instant; instantaneous
   「今いま、行動こうどうを起おこせ」という、それが伝つたえる実際的じっさいてきな意味いみに加くわえて、即座そくざの行動こうどうがなぜ重要じゅうようであるかという多おおくの理由りゆうをも、言外げんがいに示唆しさしていたのであった。↗

   "Act now!" he said, and in addition to his obvious meaning, he hinted that there were number of other important reasons why immediate action was needed.

• Synonym即時そくじNeutralNeutral. Means immediate or real-time, as in 「即時決済」; 「即座」 usually appears as 「即座に」, stressing an instant on-the-spot reaction.
• Related即時性そくじせいWrittenWritten/formal prose. Names the quality of being prompt or immediate, as in 「情報の即時性」; 「即座」 stresses acting right there on the spot.
• Antonym後日ごじつNeutralNeutral. Means another day or some future date; where 「即座」 is right now on the spot, this pushes the action to a later day.
• Antonym後刻ごこくFormalFormal. Means a little later, as in 「後刻ご連絡します」; it contrasts with 「即座」 as 'later on' versus 'right now, on the spot'.

For acting at once, on the spot, 「即座に」 is the usual choice, as in 「即座に答える」. Use 「即時」 for immediate or real-time handling, and 「即時性」 for immediacy as a quality. The opposites are 「後刻」 and 「後日」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. その場ば。
2. その場ばですぐ行おこなうこと。