This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
榸 combines 木 (tree) with 埋 (bury), but the exact historical development and original meaning are uncertain.
The left side is a tree 木, and the right side is 埋 (bury). Picture a dead tree being buried, like a stump or fallen log.
For タイ, imagine tying a rope around a buried tree stump: tie -> タイ, and the rope secures the old wood.