newborn baby; neonate
Formal or medical term for a newborn infant, especially in the first few weeks of life. In everyday speech, 新生児 (しんせいじ) is more common.
A health checkup for newborns is conducted within one month after birth.
Composed of 初 (first, beginning), 生 (birth, life), and 児 (child, infant). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'newborn child'.