Jichin-sai (also pronounced "tokoshizume no matsuri") is a Japanese word used to describe the ground-breaking ceremony that is performed prior to the construction of an architectural structure or civil engineering work in order to appease the Shinto god or spirit of the land (known in Japanese as the Ujigami, the guardian god or spirit of the family or the community) and receive permission to use the land.
地鎮祭（じちんさい・とこしずめのまつり）は、土木工事や建築などで工事を始める前に行う、その土地の神(神道)（氏神）を鎮め、土地を利用させてもらうことの許しを得る。