noun
orphan; parentless child
A child who has lost both parents or has been abandoned. Slightly literary or formal; in everyday speech 孤児 (こじ) is more common.
戦争で親なし子になった子どもたちが大勢いた。
There were many children who became orphans because of the war.
彼は親なし子として施設で育った。
He grew up in an institution as an orphan.
Compound of 親 (おや, 'parent') + なし ('without') + 子 (こ, 'child'), literally 'child without parents'. The reading ご is a rendaku form of 子.