环

Left jade radical — the indexing radical (it looks like 王 'king' but is actually the contracted form of 玉 'jade', with the dot dropped in left-side position). Anchors the original meaning: 环 was a flat circular jade ornament with a hole in the middle, the most prized type of bi-disc. Same radical in 玩 (play), 现 (appear), 玲 (tinkling jade).

Right component supplies the sound, substantially shifted from huán. The simplified 环 swapped in 不 as a stroke-count saver in place of the traditional 環's complex 睘 phonetic (eye 目 over garment 衣, picturing a person admiring a jade ring at neck level). The original etymology was vivid; simplification trades that for ease of writing.