This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 尵 is uncertain. It visually combines 尢 (lame) with 貴, but the original semantic and phonetic roles are unclear.
The outer 尢 suggests a physical impairment, and the inner 貴 suggests something precious. Imagine a precious horse that has fallen lame, tying to the kun-reading うまがや.む (horse falling ill).
For タイ, picture a tired horse that is lame and needs a tie to rest: tie -> タイ, and the horse is うまがや.む.