infant

From Latin 'infans', meaning 'unable to speak, speechless'.

NOUN (1)
[/ˈɪn.fənt/en-US]
baby common / newborn commonformal / toddler informal / little one informal / concept of early childhood untranslatable (Refers to the broader concept encompassing the early stages of a child's development and might not have a single word counterpart.)
Synonyms baby common , newborn commonformal , toddler informal
Antonyms adult , teenager

An infant is a very young child, typically one who is less than one year old. This term often refers specifically to a baby during its earliest stages of life, characterized by rapid growth and development. The word originates from Latin 'infans', meaning 'unable to speak, speechless', which emphasizes the early developmental stage of children. Infants are largely dependent on adults for care and nurturing.

nouns referring to a stage in life are generally not irregular
plural
infants
  • The baby slept peacefully in her crib. — 赤ちゃんはクレードルで平和に眠っていました。
  • Parents must pay close attention to their infant's needs. — 親は幼児のニーズに細心の注意を払う必要があります。
  • She is excited to see her newborn for the first time. — 彼女は自分の新生児を初めて見ることに興奮しています。
  • The toddler was learning to walk with assistance. — 幼児は補助を受けて歩くことを学んでいました.
register: formal