When you are having fun, you are having a good time. Watching little kids jump around inside an inflatable bouncy house, you can instantly tell how much fun they're having.

There is no mistaking fun when you're having it, and it's generally used to mean exactly what it sounds like, some activity or experience that's purely enjoyable. When fun takes the form of an adjective, it's informal, not strictly grammatically correct. So while you can say, "Being with her is so much fun," you can't correctly say, "She is such a fun girl." Fun turns a little bit mean when you're making fun of, or teasing, your friend. In this case, it might be fun for you, but it's probably not very much fun for him.

Definitions of fun
  1. noun
    activities that are enjoyable or amusing
    “I do it for the fun of it”
    “he is fun to have around”
    synonyms: merriment, playfulness
    see moresee less
    type of:
    diversion, recreation
    an activity that diverts or amuses or stimulates
  2. noun
    a disposition to find (or make) causes for amusement
    “he was fun to be with”
    synonyms: playfulness
    see moresee less
    show 5 types...
    hide 5 types...
    playful humor
    archness, impertinence, perkiness, pertness, sauciness
    inappropriate playfulness
    friskiness, frolicsomeness, sportiveness
    lively high-spirited playfulness
    impishness, mischievousness, puckishness, whimsicality
    the trait of behaving like an imp
    humor, humour, sense of humor, sense of humour
    the trait of appreciating (and being able to express) the humorous
    type of:
    frivolity, frivolousness
    the trait of being frivolous; not serious or sensible
  3. noun
    verbal wit or mockery (often at another's expense but not to be taken seriously)
    “he became a figure of fun
    synonyms: play, sport
    see moresee less
    show 4 types...
    hide 4 types...
    jocosity, jocularity
    fun characterized by humor
    waggery, waggishness
    waggish behavior
    clowning, comedy, drollery, funniness
    a comic incident or series of incidents
    paronomasia, pun, punning, wordplay
    a humorous play on words
    type of:
    humor, humour, wit, witticism, wittiness
    a message whose ingenuity or verbal skill or incongruity has the power to evoke laughter
  4. noun
    violent and excited activity
    “she asked for money and then the fun began”
    “they began to fight like fun
    see moresee less
    type of:
    any specific behavior
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