abrogate, terminate, discard
廢 centers on the act of formally ending or discarding something: abrogating a rule, terminating a practice, or throwing something away as no longer useful.
廢 combines 广 (building) with 發, which likely contributes the sound and the idea of shooting or setting in motion, together suggesting the act of discarding or abolishing something from a structure. The modern Japanese simplified form is 廃.
Inside a building (广), the complex shape 發 suggests something being thrown out or set aside. Picture a rule being physically removed from a building and discarded.
For ハイ, imagine a high official saying 'Hi!' as they abrogate an old law: Hi -> ハイ, and the rule is terminated with a wave.