young and without experience 幼稚无经验的；未谙世事的 a callow youth 乳臭未干的年轻人
Oxford Collocations DictionaryCallow is used with these nouns:- youth
Word OriginOld English calu ‘bald’, of West Germanic origin, probably from Latin calvus ‘bald’. This was extended to mean ‘unfledged’, which led to the present sense ‘immature’.