Japanese More information Kanji in this term ... Kanji in this term 蝶 形 骨 ちょうJinmeiyō けいGrade: 2 こつGrade: 6 kan'on Close 蝶形骨 on Japanese Wikipedia Etymology 蝶形 (“butterfly shape”) + 骨 (“bone”) Pronunciation (Tokyo) ちょーけーこつ [chòókéꜜèkòtsù] (Nakadaka – [3])IPA(key): [t͡ɕo̞ːke̞ːko̞t͡sɨ] Noun 蝶(ちょう)形(けい)骨(こつ) • (chōkeikotsu) ←てふけいこつ (tefukeikotu)? a sphenoid bone Meronym: 翼状突起 (yokujō tokki) Wikiwand - on Seamless Wikipedia browsing. On steroids.