expression, noun
Rare literary expression meaning a beloved person or treasured thing. Cross-referenced with 掌の玉, which is a more common variant.
See also: 掌の玉
「手底の玉」は、掌の玉と同じく、最愛の者を指す古風な言い回しである。
手底の玉, like 掌の玉, is an old-fashioned expression for one's most beloved person.