Антонимом very immature

adult grown-up mature matured ripe experienced grown old older senile full-grown ripened full-blown fully-grown fully grown fully fledged developed sophisticated sensible advanced full-fledged manly adultish serious elderly responsible aged wise senior veteran complete doddering ancient ageing hoary decrepit seasoned established aging initiated fully developed of age matronly moribund dying fledged refined later higher progressive infant distinct gray olden worldly grey weary tired decaying waning worldly-wise considered settled stable big middle-aged grownup evolved improved over the hill mellow reasonable rational perfected down-to-earth soft fully-developed highly developed full grown levelheaded tender geriatric centenarian grizzled octogenarian nonagenarian septuagenarian senescent venerable grown up tottering dilapidated frayed rickety antiquated tattered worn out

developed fully-fledged ripened full-blown

manly sensible sophisticated adultish serious wise full-grown fully-grown fully grown fully fledged

cosmopolitan experienced knowing sophisticated worldly worldly-wise cultured earthly material refined mature knowledgeable astute cultivated enlightened grasping perceptive seasoned hardened shrewd guileful streetwise smart wise politic aware matured worldly-minded street smart street-smart educated advanced deceitful dishonest upper-class artful savvy wily intelligent worldly wise well-traveled

experienced adult grown-up mature ripe familiar knowledgeable practiced practised seasoned skilled tasty trained versed educated old schooled accomplished qualified veteran professional expert adept proficient competent capable great master skillful consummate ace good crackerjack virtuoso skilful masterful adroit crack savvy tried well versed pro worldly accustomed well-versed hardened long-serving polished elite cultivated excellent exceptional able fine specialist cultured initiated clever apt wonderful au fait magnificent outstanding marvellous superb talented brilliant stellar professed handy dexterous sharp complete dazzling class mean knowing slick bravura leet genius sophisticated top-notch first-rate first-class out of this world dextrous marvelous tested weathered up to speed worldly-wise long-time old-time inured wise to ways battle-scarred old hand not born yesterday been around been there in the know broken in of the old school masterly dynamite refined instructed well trained

sensible significant meaningful intelligent serious bright profound smart weighty worthwhile

old ancient outdated aged antediluvian antiquated dated expired archaic defunct extinct fusty obsolete outmoded antique mediaeval medieval obsolescent outworn passé prehistoric prehistorical rusty creaky moribund neolithic parachronistic out of date

apt brainy bright brilliant clever fast hyperintelligent intelligent keen nimble quick quick-witted sharp sharp-witted smart supersmart ultrasmart

sensible judicious prudent sagacious sage sane sapient sound wise considered intelligent smart thoughtful shrewd perceptive astute worldly serious mature reasonable rational responsible logical unfrivolous sober earnest pragmatic learned punctilious cultured meticulous dependable sophisticated levelheaded reasoned enlightened refined well-grounded serious-minded level-headed sharp insightful discerning clever guileful profound crafty cynical wily observant knowing foxy alert accurate untrusting discriminating acute tricky hardheaded savvy sceptical farsighted calculating devious wary ingenious argute incredulous cunning perspicacious calculated unbelieving suspecting streetwise suspicious sly heady subtle slick artful beguiling astucious canny scheming brainy skeptical sharp-witted clear-sighted clear-eyed wised up quick-witted on the ball

perfect flawless faultless impeccable complete developed exact finished excellent happy healthy infallible moral pure unblemished unflawed well functional practical useful well developed

complicated jaded untrusting

careful cautious wise

big biggish considerable goodly grand great handsome husky king-size king-sized large largish outsize outsized overscale overscaled oversize oversized sizable sizeable substantial tidy whacking whopping huge king size

afraid cowardly fearful meek reasonable shy timid

manifest active functioning employed live realised realized patent alive apparent clear conspicuous evident obvious operating operative expressed going living on open overt running visible working developed

very important very important person very inconsistent very interested very interesting very keen very image very hungry very hot very hard very great very good