軌道長半径 きどうちょうはんけい Meanings Noun semi-major axis (esp. in orbital matters) Kanji 軌 track. Read as キ. 道 road. Read as ドウ. 長 long. Read as チョウ. 半 half. Read as ハン. 径 diameter. Read as ケイ. Jinuma: Japanese Dictionary · Word lists