• 墓地ぼち — cemetery
• 墓参ぼさん — visiting a grave
• 墓穴ぼけつ — grave hole / “digging one’s own grave”
• 墓前ぼぜん — in front of a grave
• 墓標ぼひょう — grave marker

墓 combines 土 (earth/soil) with 莫 (to cover/darkness), symbolizing something covered by soil. It naturally came to represent a grave or tomb — a place of burial and remembrance. The kanji is strongly tied to Japanese memorial traditions such as お盆 and 命日.

祖父そふの 墓はかに 花はなを 供そなえた。
I offered flowers at my grandfather’s grave.

お盆ぼんには 家族かぞくで 墓参ぼさんに 行いきます。
We visit the family grave together during Obon.