径 is built from the 彳 (step / going) and 巠 (warp thread (in 経·軽)) components.
It belongs to a phonetic family with 経, 軽, and 茎 — they share the 巠 component and the reading ケイ.
A common word using 径 is 直径 (ちょっけい), meaning “diameter”.
Don't confuse it with 経, 軽, and 茎.
