noun
Refers to the period of early childhood, typically from birth to around age 6 or 7. Often used in developmental or educational contexts.
幼年期の経験は人格形成に大きな影響を与える。
Experiences in childhood have a great influence on personality development.
彼は幼年期を田舎で過ごした
He spent his childhood in the countryside.
幼児期 is often used interchangeably with 幼年期, but can specifically refer to the toddler/preschool stage (ages 1–6).
Compound of 幼年 (yōnen, 'childhood') + 期 (ki, 'period'). The word is a straightforward Sino-Japanese term.