Bottom-and-left
辶 is the walking radical - the compressed form of
辵, picturing a foot in motion. Indexing radical, putting
迅 in the family of going-and-moving verbs (
进 enter,
退 retreat,
迎 welcome,
追 chase). Carries the core meaning:
迅 names a speedy, swift motion, so the radical does the semantic work.
