Someone who is mature acts grown up, like an adult. However, when one sister says to another, "That's so mature," she's usually using the word sarcastically, because her sister has done something very immature, like sticking out her tongue.

The adjective mature doesn't only describe advancing age, although the residents of a senior citizens' home could definitely be considered mature. Anything that is fully developed, like an aged cheese or bottle of wine, can also be called mature. The word can also refer to something that is only appropriate for people who are considered legal adults, like the movie that is for "mature audiences only."

Definitions of mature
  1. adjective
    having reached full natural growth or development
    “a mature cell”
    adult, big, full-grown, fully grown, grown, grownup
    (of animals) fully developed
    abloom, efflorescent
    bursting into flower
    capable of bearing fruit
    full-blown, matured
    fully ripe; at the height of bloom
    of leafy vegetables; having formed into a head
    marriageable, nubile
    of girls or women who are eligible to marry
    past the stage of full bloom
    meridian, prime
    being at the best stage of development
    (used especially of persons) having lived for a relatively long time or attained a specific age
    see moresee less
    not yet mature
    in the state of development between puberty and maturity
    embryologic, embryonal, embryonic
    of an organism prior to birth or hatching
    beginning to develop
    immature of its kind; especially being or characteristic of immature insects in the newly hatched wormlike feeding stage
    prepubertal, prepubescent
    (especially of human beings) at the age immediately before puberty; often marked by accelerated growth
    of an inactive stage in the development of some insects, between the larval and the pupal stages
    (of animals especially human beings) having arrived at the onset of puberty (the age at which sex glands become functional) but not yet fully mature
    of the insects in the chrysalis (cocoon) or post larval stage
    not yet fully developed
    born after a gestation period of less than the normal time
    immature, young
    (used of living things especially persons) in an early period of life or development or growth
    show more antonyms...
  2. adjective
    fully developed or matured and ready to be eaten or used
    synonyms: ripe
    aged, ripened
    of wines, fruit, cheeses; having reached a desired or final condition; (`aged' pronounced as one syllable)
    mellow, mellowed
    having a full and pleasing flavor through proper aging
    too ripe and beginning to turn soft
    see moresee less
    green, immature, unripe, unripened
    not fully developed or mature; not ripe
    not subjected to an aging process
    show more antonyms...
  3. adjective
    (of birds) having developed feathers or plumage; often used in combination
    synonyms: fledged
    fledgeling, fledgling
    (of a young bird) having acquired its flight feathers
    full-fledged, fully fledged
    (of a bird) having reached full development with fully grown adult plumage; ready to fly
    see moresee less
    immature, unfledged
    (of birds) not yet having developed feathers
    not having feathers
    show more antonyms...
  4. adjective
    fully considered and perfected
    mature plans”
    synonyms: matured
    being changed over time so as to be e.g. stronger or more complete or more useful
  5. adjective
    characteristic of maturity
    mature for her age”
    characteristic of late maturity verging on decline
    mellow, mellowed
    having attained to kindliness or gentleness through age and experience
    at the highest point of development especially in judgment or knowledge
    see moresee less
    characteristic of a lack of maturity
    adolescent, jejune, juvenile, puerile, sophomoric
    displaying or suggesting a lack of maturity
    characteristic of a baby
    childish, infantile
    indicating a lack of maturity
    show more antonyms...
  6. verb
    develop and reach maturity; undergo maturation
    “He matured fast”
    synonyms: grow, maturate
    see moresee less
    show 4 types...
    hide 4 types...
    grow ripe
    find, find oneself
    accept and make use of one's personality, abilities, and situation
    grow up
    become an adult
    come of age
    reach a certain age that marks a transition to maturity
    type of:
    grow, progress, unfold, or evolve through a process of evolution, natural growth, differentiation, or a conducive environment
  7. verb
    grow old or older
    synonyms: age, get on, maturate, senesce
    see moresee less
    become officially one year older
    fossilise, fossilize
    become mentally inflexible
    be foolish or senile due to old age
    type of:
    grow, progress, unfold, or evolve through a process of evolution, natural growth, differentiation, or a conducive environment
  8. verb
    cause to ripen or develop fully
    “Age matures a good wine”
    synonyms: ripen
    see moresee less
    type of:
    alter, change, modify
    cause to change; make different; cause a transformation
  9. verb
    develop and work out fully in one's mind
    “I need to mature my thoughts”
    see moresee less
    type of:
    develop, explicate, formulate
    elaborate, as of theories and hypotheses
  10. verb
    become due for repayment
    “These bonds mature in 2005”
    see moresee less
    type of:
    undergo a change; become different in essence; losing one's or its original nature
  11. verb
    cause to ripen and discharge pus
    synonyms: suppurate
    fester, maturate, suppurate
    ripen and generate pus
    see moresee less
    type of:
    cause to localize at one point
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