幼子・幼な子・幼児|おさなごosanago[3]nakadaka (mid-high)

1. nouninfant; baby; little child

• Synonym赤ん坊あかんぼうNeutralA baby, common in everyday use; younger than 「幼子」, mostly up to a year or two after birth.
• Synonym赤子あかごNeutralA baby, as in 「赤子の手をひねる」; when read せきし it is a metaphor for the common people.
• Synonym赤ちゃんあかちゃんCasualA baby said with affection; the most common everyday word, and for a younger child than 「幼子」.
• Synonym乳児にゅうじFormalAn infant up to about one year old; a formal medical and administrative term, kept distinct from 「幼児」.
• SynonymベビーNeutralA loanword for baby, mostly used as a prefix, as in 「ベビーカー」 and 「ベビー服」.
• SynonymみどりごWrittenA newborn baby; an archaic, literary word found mainly in literature and religious writing.
• Synonym乳飲み子ちのみごNeutralA baby still at the breast; stresses the nursing stage and carries an affectionate nuance.
• Antonym大人おとなNeutralAn adult; the antonym of the young 「幼子」.
• Antonym老人ろうじんNeutralAn elderly person; stands at the opposite end of the age scale from a small 「幼子」.

Use 「幼子」 for a young child, with an affectionate nuance and mostly in written prose. For a baby say 「赤ちゃん」 or 「赤ん坊」; in medical or administrative language use 「乳児」 (with 「幼児」 for toddlers). The antonym is 「大人」.

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

1. 幼おさない子供こども。満まん一いち歳さいから小学校しょうがっこう就学しゅうがくまでの子供こども。