⑨

⑨ U+2468, ⑨ CIRCLED DIGIT NINE ← ⑧ [U+2467] Enclosed Alphanumerics ⑩ → [U+2469]

Circled digit 9.

⑨

1. (astronomy, no fill) The asteroid 9 Metis.
2. (go) The ninth (white or black) stone played in a position.

See ①

• (astronomy, dated):

⑨(まるきゅう) • (maru-kyū) 

1. The number 9 enclosed in a circle, used in enumerating lists.

A diagram of gameplay in the manual of Phantasmagoria of Flower View labelled Cirno with the legend "⑨ (⑨)" and the key "9. Idiot".

⑨(まるきゅう) or ⑨(ばか) or ⑨(きゅう) • (maru-kyū or baka or kyū) 

1. (Can we verify⁽⁺⁾ this sense?) (fandom slang, endearing) The Touhou character Cirno, known affectionately as an idiot.
   • 2008, “⑨destiny ～ ずっとチルノのターン”, in bit (lyrics), Rebirth, performed by Silver Forest:

     ⑨(まるきゅう)って言(い)うな～

     Marukyū tte iu na~

     Don't call me nineball~