part of speech: adjective

inflections: faster, fastest

definition 1: moving or operating with speed.

  • He’s a fast runner.
  • She drives a fast car.

synonyms: quick, rapid

antonyms: slack, slow

definition 2: done in a short time.

  • She prepared a fast meal.

synonyms: quick

antonyms: slow

definition 3: true and loyal.

  • Meg and I are fast friends.

synonyms: devoted, faithful, firm, steadfast, steady, true

definition 4: fixed or firmly attached.

  • I tried to shake him off, but he had a fast grip on my arm.

synonyms: fixed, secure, stable, stationary, tight

antonyms: loose

definition 5: ahead of the correct time.

  • That clock is five minutes fast.

definition 6: not easily faded; fixed firmly.

  • The blue in this shirt won’t wash out because the color is fast.

antonyms: temporary



part of speech: adverb

inflections: faster, fastest

definition 1: with speed; quickly.

  • He came fast when his mother called him for dinner.

synonyms: at full tilt, quickly, rapidly

antonyms: slowly

definition 2: tightly; firmly.

  • She held fast to her child’s hand.

synonyms: firmly, securely, tightly

antonyms: loosely

definition 3: deeply; soundly.

  • We fell fast asleep.

synonyms: soundly