sparrow, revolve, place name
雟 is a rare kanji whose given meanings do not share one clear conceptual center. It can refer to a sparrow, the idea of revolving or circling, and a place name. Treat these as separate, loosely connected senses.
The historical development of 雟 is uncertain. It visually combines 屮, 隹, and 冏, but the original semantic and phonetic roles of these components are unclear.
The top 屮 suggests a sprout, the middle 隹 is a bird, and the bottom 冏 looks like a bright opening. Picture a sparrow flying in circles around a bright sprout in a place named after this scene.
For ケイ, imagine a sparrow circling a bright sprout while making a sharp 'kay' sound: kay -> ケイ.