Not used independently in modern Chinese; it is best known in the posthumous title 隋炀帝 (Emperor Yang of Sui). The right side 昜 is the phonetic — the original full form behind the 阳 of 太阳 and the right side of 场.
register
Classical and historical-title use only; not part of modern speech.
On the right, 昜 supplies the sound. It is the unsimplified ancestor of the 阳 phonetic, also driving 扬 and 杨; its 'rising heat' sense suits a fire word.