【Youthful】 , 【juvenile】 ,  【puerile】 ,  【boyish】 ,  【virgin】 ,  【virginal】 ,  【maiden】  are comparable when they mean relating to or characteristic of one who is between childhood and adulthood; although their basic meaning is the same, they are seldom interchangeable because of widely differing implications and applications.

【Youthful】 suggests the possession or the appearance of youth, or of qualities appropriate to youth; it can be employed laudatorily or in extenuation.

【Juvenile】 often suggests immaturity of mind or body or lack of experience; it is applied especially to what is suited to or designed for boys and girls in their early teens.

【Puerile】 is applied especially to acts and utterances which, though excusable in a boy or girl or characteristic of immaturity, would be unpardonable or out of character in an adult; the word finds its commonest use in depreciatory reference to acts or utterances of the mature.

【Boyish】  (compare mannish under MALE ), though referred commonly to boys, is sometimes used in reference to girls or their clothes, appearance, or qualities. The term often suggests some of the engaging qualities or the physical attractiveness of normal, vigorous boys.

【Virgin】  and  【virginal】 , though referable usually to girls, in the extended use in which they suggest the freshness, innocence, purity, and inexperience that are associated with 【youthful】 virginity are applicable also to boys.

【Maiden】  in its extended sense carries an even stronger suggestion than  【virgin】  or  【virginal】 of 【youthful】 lack of experience; it also implies that one's qualities (as virtue, worth, competence, or strength) have not been tried or tested.