also: いみこ
noun
unwanted child; shunned child
Refers to a child who is avoided or rejected, often due to superstition, taboo, or being seen as a bad omen. The term carries a strong negative and somewhat archaic or folkloric tone.
その村では、昔、忌み子とされた子供は村外れに住まわされたという。
In that village, long ago, children who were considered shunned were said to have been made to live on the outskirts.
彼は自分が忌み子のように扱われていると感じていた。
He felt as if he were being treated like an unwanted child.
Compound of 忌み (imi, 'abstinence, taboo, mourning') and 子 (ko, 'child'). The exact historical origin is uncertain, but the term likely arose from folk beliefs where certain children were considered inauspicious or ritually impure.