He was a young fellow, very green, very immature.

他是个年轻的家伙，没什么经验，很不成熟。

《柯林斯英汉双解大词典》

In other words, he's a little immature.

换句话说，他不太成熟。

youdao

The test outlined a security issue due to a possible immature implementation of the IPv6 protocol.

这项测试概述了一个可能由于当前IPv 6协议应用的不成熟导致的安全隐患。

youdao

"It was an inexperienced, immature driver who felt that he was invincible, driving at night with a carload of kids.

VOA: special.2010.07.01

What's different from an immature cell and a mature cell?

不成熟细胞和成熟细胞间的差异是什么

耶鲁公开课 - 生物医学工程探索课程节选

Similarly, if you're dealing with immature humans and you want your child to get you a beer, you can't just sit, wait for the kid to give you a beer and uncap the bottle " and say, "Excellent. Good. Hugs."

类似的，如果你要训练的是未成年人,如果你想让你的孩子帮你拿一罐啤酒，你就不能只是坐着，等孩子把啤酒拿给你,然后你打开瓶盖,说，“太棒了，来抱一下“

耶鲁公开课 - 心理学导论课程节选

And in an industry which is about 40yrs old and relatively immature on a program which runs out over 10yrs, I would expect that there will be supplier failure and delivery failure in parts and it is my responsibility to plan for that.

BBC

Baby limas are not immature Fordhooks but a separate variety that are smaller, less starchy and more delicate tasting.

NPR: Falling in Love with Limas

One of these was smashed and had leaked a broad puddle of immature wine across the floor, leaving a sticky residue.

BBC: CLOUD ATLAS, BY DAVID MITCHELL