Definition of 「燨」:
1. Anciently the same as "爔".
古同“爔”。
2. Phonetic and semantic component: composed of "日" (sun) and "羲" (xǐ) as the phonetic part.
Basic meaning: the sun, sunlight.
Example: "东曦既驾" — from "聊斋志异·促织".
形声。从日,羲(xǐ)声。本义:太阳,阳光。东曦既驾——《聊斋志异·促织》
3. It is interchangeable with "羲," for example, "曦和" (which refers to "羲和," a term encompassing both the Xi and He clans, known as the celestial officials during the reign of Yao who were responsible for astronomy and calendars).
通“羲” 如:曦和(即羲和。羲氏与和氏的并称。为传说中尧时执掌天文历法的官吏)