Answer: youthful

AnswerCrossword Clue
YOUTHFULLike kids' enthusiasm
YOUTHFULActing like a kid
YOUTHFULVigorous; active
YOUTHFULVernal
youthfulTypical or characteristic of young people
youthfulYoung or seeming young
youthfulyoung (youthful)