puerile (adj.)

• asinine
• babyish
• beardless
• boyish
• boylike
• childish
• childlike
• coltish
• foolish
• girlish
• immature
• inconsequential
• infantile
• insignificant
• irresponsible
• juvenile
• maiden
• maidenly
• puppyish
• puppylike
• ridiculous
• shallow
• silly
• trivial