characterized by youth; young.

of, pertaining to, or befitting youth

youthful enthusiasm.

having the appearance, freshness, vigor, etc., of youth

She is 60 but her optimism has kept her youthful.

in an early period of existence; early in time.

Physical Geography . (of topographical features) having undergone erosion to a slight extent only.

adjective

experienced , mature , old , adult , manly

adjective

active , adolescent , boyish , budding , buoyant , callow , childish , childlike , enthusiastic , fresh , full of life , girlish , green * , inexperienced , infant , juvenile , keen , pubescent , puerile , tender , underage , vernal , vigorous , youngnotes:to be young is to be immature or not old; to be youthful is having the attractive qualities of a young person , green , immature , new , young