grave; tomb
墓(はか)、墓地(ぼち)
grave, cemetery
On-reading (ボ) is used in compounds; kun-reading (はか) is used standalone or with okurigana.
From the JLP Quiz question bank — the word in the form it is actually tested in.
人々は先祖のお墓参りをしたり、仏壇に花や食べ物を供えたりします。
Answer: 8月13日から16日ごろ