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pillar; post
support; prop; mainstay
counter for buddhas, gods, nobles, etc.
「柱」 has other readings with different meanings.
柱に頭をぶつけてしまった。
I bumped my head on the pillar.
この家は太い柱で支えられている。
This house is supported by thick pillars.
この建物の柱はとても太くて強いです。
The pillars of this building are very thick and strong.