1.  Also AUM; the Universal sound of Creation that manifests in all things.

2.  In Hinduism, the sound that is the source of all. It has its own symbol in Sanskrit. It is traditionally pronounced Ah-oo-mm, starting in the back of the throat, moving to the center of the mouth and ending with closed lips, metaphorically representing all sounds. Also pronounced in other ways (such as “ohm”) depending upon purpose, dialect, etc. It is used as a start to most Hindu mantras.