Sacred syllable commonly written as ‘Oṃ’ or ‘Om’, which is also used in Hinduism and Buddhism. Jains use it, for instance, in the Namaskāra-mantra. The letters in the word are significant:

• ‘A’ refers to Arhats, siddhas and ācāryas
• ‘U’ refers to preceptors or teachers
• ‘M’ refers to mendicant.