Something happens instantly when there's no pause or delay at all before it occurs. If you fall asleep as soon as your head touches your pillow, you can say you drifted off instantly.

If an event is immediate, it happens instantly. Your parents might say they fell in love instantly, the moment they first saw each other, and you may realize instantly on the first day of school that you are going to love your history class. The adverb instantly first meant "persistently," rather than "immediately," though it soon gained this meaning. The Medieval Latin root is instantem, "pressing, urgent," or "standing near."

Definitions of instantly
  1. adverb
    without delay or hesitation; with no time intervening
  2. adverb
    without any delay
Word Family

Test prep from the experts

Boost your test score with programs developed by’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week