Wikipedia describes samadhi as
Samadhi (Sanskrit: समाधि, Hindi pronunciation: [səˈmaːd̪ʱi]), also called samāpatti, in Hinduism, Buddhism, Jainism, Sikhism and yogic schools refers to a state of meditative consciousness. It is a meditative absorption or trance, attained by the practice of dhyāna. In samādhi the mind becomes still. It is a state of being totally aware of the present moment; a one-pointedness of mind.
But I've heard the word samadhi being used for graves in south Indian languages (especially Kannada). I'm not sure if the same word is used in other Indian languages too.
Other than the word samadhi's usage in yoga, is it also an exact Sanskrit translation for a grave?