This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
憼 combines 敬 (respect, caution) with 心 (heart), suggesting a heart full of caution or reverence. The exact historical development is uncertain.
The top part 敬 suggests respect or caution, and the bottom 心 is the heart. Together they hint at a cautious, respectful heart, but the exact meaning is unclear.
For ケイ, imagine a cautious person named Kay who always acts with a respectful heart: Kay -> ケイ.