This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
窹 is a rare character. It combines 穴 (hole, cavity) with 吾, which may contribute sound. The exact historical development is uncertain.
The top 穴 suggests a cave or hole. The bottom 吾 (oneself) might hint at a personal hearth or stove, but the meaning is unclear. Picture a hidden stove inside a cave.
For ゴ, imagine a go (碁) board placed inside a cave-like stove: go -> ゴ, and the stove is a rare, hidden place.