履 is largely literary or formal in modern Chinese, surviving mainly in compounds: 履行 (to fulfill — duties, contracts), 履历 (résumé / CV), 履约 (to honor an agreement), and the chengyu 如履薄冰 ('as if treading on thin ice' — to act with extreme caution).
history
Originally meant 'shoe' — pre-Qin texts use 履 where later texts use 鞋. The verb sense 'to tread' extended naturally from 'to wear shoes', and from there to the abstract 'to fulfill (a path, a duty)'.
Upper-left body radical, three strokes for a person sitting or lying down. Anchors 履 in the body family, here the body in motion — walking, treading, wearing shoes. Originally a person striding forward in shoes; same family: 居, 屋, 屐.
phonetic
復fù
to return; repeat
Inside 復 supplies both sound and meaning — it means 'to walk back the same path, to repeat', combining with the body radical for a person treading and re-treading a road. From that came 履行 (to carry out, walk through obligations) and 步履 (gait).
