小児|しょうにshouni[1]atamadaka (head-high)

1. nounyoung child; infant
   彼かれは五ご歳さいの時ときに小児しょうに麻痺まひにかかった。↗

   He was struck with polio when he was five.

• Synonym児童じどうWrittenWritten/formal: children in general, common in education and welfare; under the 「児童福祉法」 it covers anyone under 18. 「小児」 is mostly medical, as in 「小児科」.
• Synonym童子どうじWrittenWritten: a boy, or a young boy who attends on a noble; 「小児」 is a medical term.
• SynonymキッドCasualLoanword that in Japanese really means a young goat or kid leather, so it cannot replace 「小児」; for children it appears only in names and the like.
• Synonym小さ童ちいさわらわWrittenWritten, archaic: a young child serving in the Heian-period imperial palace; 「小児」 is a modern medical term.
• Synonym児じWrittenWritten single character for a boy, mostly used as a suffix as in 「幼児」; 「小児」 is a standalone word.
• Synonym童わらべWrittenWritten, with a quaint, nursery-rhyme flavor as in 「わらべ歌」; 「小児」 leans medical.
• SynonymちびっこCasualColloquial, affectionate way to refer to a small child; 「小児」 is medical written language.
• Related坊やぼうやCasualColloquial: a little boy, or a naive young man who knows nothing of the world; 「小児」 is a medical term.
• RelatedちびCasualColloquial: a tiny child or short person, used with affection or disdain; 「小児」 is neutral.
• RelatedこわっぱCasualColloquial and rather coarse, old-fashioned term for a mischievous, cheeky boy, with a contemptuous nuance; 「小児」 is a neutral medical word.
• RelatedわっぱWrittenWritten, with a quaint, nursery-rhyme flavor as in 「わらべ歌」; 「小児」 leans medical.
• Related孺子じゅしWrittenWritten: a child, or a contemptuous label for a green youth; 「小児」 is neutral.
• Related鼻たれはなたれCasualColloquial: a runny-nosed child, or figuratively a greenhorn; 「小児」 is neutral.
• Related稚ややWrittenWritten, archaic word for an infant or young child; in modern usage say 「小児」 or 「幼児」.
• Antonym成人せいじんNeutralAn adult, the counterpart of 「小児」.
• Antonym大人おとなNeutralA grown-up, the opposite of 「小児」.

Use 「小児」 for children in medical contexts, as in 「小児科」. For children in law and education use 「児童」; for affectionate talk pick 「ちびっ子」 or 「坊や」; 「童」 adds an archaic, poetic flavor. The opposites are 「成人」 and 「大人」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 小ちいさな子供こども。幼おさない子供こども。幼児ようじ。
2. 医学いがく上じょうの子供こども。年齢ねんれいについては諸説しょせつある。