noun
pinworm; threadworm
A small parasitic worm (Enterobius vermicularis) that commonly infects the human intestine, especially in children.
ぎょう虫は子供に多い寄生虫です。
Pinworms are a parasite common in children.
ぎょう虫の検査をしました。
I had a pinworm test.
The kanji 蟯 is a specific character for pinworm, but its origin is uncertain. The reading ぎょう is the on'yomi of 蟯, and 虫 means 'worm' or 'insect'.