infant
/ˈɪnfənt/noun
1- a very young child or baby幼儿; 婴儿。
1.1
- Brit. a schoolchild between the ages of five and seven〈英〉五至七岁的学童：
as modifier their first year at infant school.他们在幼儿园的第一年。
1.2
- as modifier denoting something in an early stage of its development初期的, 摇篮期的：
the infant Labour Party.
初创阶段的工党。
1.3
- Law a person who has not attained legal majority【律】未成年人。
词源
late Middle English: from Old French enfant, from Latin infant- 'unable to speak', from in- 'not' + fant- 'speaking' （from the verb fari）.