infancy
US /ˈɪn.fən.si/
UK /ˈɪn.fən.si/

1.
婴儿期, 幼年
the period of a child's life before they can walk or talk; babyhood
:
•
During infancy, babies learn to recognize faces and voices.
在婴儿期,婴儿学习识别面孔和声音。
•
The first two years of life are considered infancy.
生命的前两年被认为是婴儿期。