1. 未成年：4. preposition 在(要求、标准等)以下;未满 | under age : 未成年 | 5. preposition 在...从属下;尤指:受制于;根据

2. 未成年; 未到规定年龄：to all ages 直到千秋万代 | under age 未成年; 未到规定年龄 | ages ago 从前; [口]老早, 早就

3. 未成年,不够年龄：under age 未成年,不够年龄 | under control 处于控制之下,被控制住 | under one's breath 低 声 说 , 小声点儿

4. 未達法定年齡的：Under oath 在誓言下 | Under age 未達法定年齡的 | Underpayment 不足的支付

1. 未成年的；未到法定年龄的
A person who is under age is legally too young to do something, for example to drink alcohol, have sex, or vote.

e.g. Underage youths can obtain alcohol from their older friends.
未到法定年龄的青少年可以从年龄较大的朋友那里弄到酒。
e.g. ...girls who have babies when they are under age.
还未成年就已生下孩子的女孩

2. 未成年人所做的
Under age activities such as drinking or smoking are carried out by people who are legally too young to do them.

e.g. ...his efforts to stop under age drinking and drug abuse.
他为制止未成年人酗酒吸毒而作的努力