跡
セキ, あと

tracks, mark, print, impression

JLPT2 G7 S13 F953

As per 亦# (slender line) + 足 leg/foot → trail of footprints (compare 迹) → *footprint*; *traces*; *tracks* → *mark*; *sign*; *site*. For "footprints," also compare 蹟, 踪 and 蹤.

[Full Kanji Etymology List]