mani
/ˈmɑːni/(also mane)
noun
Any of various sacred objects or aids to prayer; especially a prayer wheel containing ‘Om maṇi padme hūṃ’ or other mantras, or a stone slab or wall of slabs inscribed with this or other mantras (frequently attributive in mani wall).
Origin
Early 19th century. From Tibetan ma-ṇi sometimes used elliptically to denote the mantra Om mani padme hum, and so applied metonymically to any structure or object containing this mantra.