He crouched down, holding his side.
illegitimate child; child by another woman
Archaic or literary term for a child born to a woman other than one's wife. Rare in modern conversation.
In old documents, there are descriptions of illegitimate children.
Standard kanji spelling for the side of the torso.
Mixed kana-kanji spelling; common in everyday writing.
Compound of 脇 (わき, 'armpit; side') and 腹 (はら, 'belly'), with rendaku voicing. The archaic sense 'illegitimate child' is a figurative extension.