Word

けい、わたり
diameter
Word

途、路、径
みち
road; street; way; path; course; route; lane; distance; ways (e.g. "a long ways"); the way (of proper conduct, etc.); one's way; morals; teachings (esp. Confucian or Buddhist); dogma; field (of medicine, etc.); subject; way; method; means
Word

直径

直経
ちょっけい
diameter
Word

口径

こうけい
aperture; bore; calibre; caliber
Word

半径

はんけい
radius
Word

内径

ないけい
bore; inside diameter
Word

小道

小路、小径、小逕
こみち、しょうけい
path; lane; small diameter; small radius
Word

径間

渡り間
けいかん、わたりま
distance between two points; distance between opposite supports of arch, bridge; span
Word

長径

ちょうけい
major axis
Word

行動半径

こうどうはんけい
radius of action; sphere of activity