“jewel / ball” in Japanese is 玉, read gyoku, tama (ぎょく, たま). It is a Grade 1 Kyōiku kanji, taught in year 1 of Japanese elementary school, and appears in words such as 目玉 (eyeball).
What does 玉 mean?
玉をなげる。
Same sound, different character — the classic trap. Compare them side by side: