[or more mature; most mature] 1 : having or showing the mental and emotional qualities of an adult
▪ We were surprised by how mature [=adult] she had become. ▪ She's very mature for her age. ▪ He has a mature outlook on life. ▪ His parents didn't think he was mature enough to live on his own. — opposite immature 2 a : having a fully grown or developed body : grown to full size
▪ The dog will stand three feet tall when (it has become) mature. [=when it has matured] ▪ Their bodies were mature, but they still behaved like children. ▪ mature [=adult] animals ▪ mature trees/leaves ▪ the dog's mature size [=the dog's size when it is fully grown] ▪ sexually mature [=old enough or developed enough to produce a baby] — opposite immature
b : having reached a final or desired state
▪ a mature wine/cheese — opposite immature
c : not young : middle-aged or older
▪ airline discounts for mature travelers [=for senior citizens who travel; for old people who travel] ▪ a man of mature years [=an older man] 3 a : based on careful thought
▪ a mature plan ▪ After/On mature reflection, he concluded that he had been mistaken.
b : showing the highest level of skill that a person develops
▪ an artist's mature work/style 4 finance : having reached the time when an amount of money (such as money for a government bond or an insurance policy) must be paid : due for payment
▪ The bond becomes mature in 10 years.