What is the meaning of ?

om or aum: the sacred syllable and mantra in Hinduism, Buddhism, Jainism and Sikhism

Alternative spelling of ওঁ (ō̃)

the sacred syllable and mantra in Hinduism, Buddhism, Jainism and Sikhism

om; aum

the sacred syllable and mantra in Hinduism, Buddhism, Jainism and Sikhism: om, aum

Source: wiktionary.org