Uronuku

…Originally, the act of pulling out seedlings of crops such as cabbage and radishes that were to be scattered, leaving only the best ones, and helping the good seedlings grow, was called “thinning out.” It is also called oronuku or uronuku. By extension, the word was also used to refer to the death of babies who were thought to be unable to be raised due to weakness, poverty, etc. at human birth. …

*Some of the terminology explanations that mention "Uronuku" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…本来は菜，大根など散播する作物の苗を，良好なものを残してその他を引き抜き，良苗の生育を助ける作業を〈間引き〉と呼んだ。おろぬく，うろぬくなどともいう。転じて人間の出生に当たり，虚弱，貧困などの理由で育てえないと考えた赤子を死亡させることにも，この語を用いた。…

※「うろぬく」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報