ˈyüthfəl adjective
1. : of, relating to, or appropriate for youth or the period of youth
could remember from his youthful enlisted days — J.G.Cozzens
his youthful optimism and his cheerful trust in men — Katherine McNamara
2. : not yet advanced beyond the early stage of growth or development
in the youthful shell the dorsal valve develops a nearly straight posterior … margin — J.A.Thomson b. 1881
a hotbed of youthful plants
a youthful culture — Stringfellow Barr
3. : possessing or characterized by youth : not old or mature
youthful dancers crowd the floor
the youthful pitcher handles himself like a veteran
4. : having the vitality or freshness of youth : fresh , vigorous
seems a bit dated now … but it is skillful, fluent, and youthful — Arthur Berger
a youthful octogenarian — W.J.Ghent
of the most brilliant colors and youthful cut — W.M.Thackeray
5. : having accomplished or undergone little erosion
high mountain chains of youthful topography — L.C.Reed
valleys … carved by vigorous youthful streams — Science
the youthful volcanic islands — Journal of Geology
— compare cycle of erosion
Synonyms:
juvenile , puerile , boyish , virgin , virginal , maiden : youthful indicates simply a pertinence or appropriateness to youth; it is likely to be benign or appreciative, noncommittal, or extenuating in its suggestion
in old age when the circulation to the skin is lessened, the skin loses its youthful appearance — Morris Fishbein
with bare shoulders and a little necklace, and a light blue sash, she looked the image of youthful innocence and girlish happiness — W.M.Thackeray
youthful indiscretions
juvenile often stresses the fact of youth and immaturity or of suitability to it; it may be used to stigmatize lack of adult judgment
juvenile activities
juvenile fiction
the majority of the Irish people were only mildly sympathetic with the rebels, and regarded their desperate rebellion as juvenile melodrama — Paul Blanshard
whereas adolescents looked upon this intense absorption as juvenile and had much more sophisticated attitudes — J.E.Anderson
puerile may factually describe the acts or utterances of a boy or girl, especially one quite young; it often stigmatizes childish immaturity in situations in which adult maturity can be expected or hoped for
puerile digestive upsets
it was dishonest, it was absurd, and it was puerile — Bernard De Voto
badly constructed, incoherent, puerile in conception and presentation, and written in shoddy journalese — D.S.Savage
boyish is often used in reference to the attractive or engaging qualities of normal, vigorous, unsophisticated boys
boyish ardor
boyish frankness
had always, in a shy, boyish fashion, worshipped his big brother — B.A.Williams
her features were clear-cut, her neck long and slender, her figure slim and boyish — Elizabeth Goudge
virgin stresses inexperience, especially sexual inexperience, often with accompanying ingenuousness
he was married, and the secret could be given only to a virgin youth — W.T.Corlett
the picture of youth, unprotected innocence, and humble virgin simplicity — W.M.Thackeray
virginal may be closely synonymous with virgin; it is more likely to connote chastened or pure suggestions of virgin inexperience
though she had lost long ago her virginal loveliness, she had ripened at middle age into a handsome and fruitful-looking woman — Ellen Glasgow
maiden may be a less frank synonym for virgin
a maiden aunt
or it may apply to a first effort
a maiden speech
or suggest youthful chaste inexperience
the maiden chastity and simplicity of these furnishings
the young ladies on board, whom … the Cambridge lads and their pale-faced tutor avoided with maiden coyness — W.M.Thackeray