Definition - What does Nam mean?
Nam is a Sanskrit syllable that refers to "identity" or "name," particularly the divine name (nam jap), or the true name of God. Nam serves as the root of other words, such as namkaran, which is one of the most important Hindu rituals, the newborn naming ceremony. In Sikhism, nam simaran refers to meditation, singing of hymns and contemplating God's names or qualities.
Nam is also used in conjunction with other syllables, words or sound vibrations in mantras. Mantras are chanted in yoga practice and meditation to still the mind and focus concentration on a single thought or purpose.
Yogapedia explains Nam
One of the most common and widely used mantras in Kundalini yoga is sat nam. Sat translates as “truth” or the “reality of existence,” so sat nam means “true identity.” It has also been translated as “truth is our identity.” “Truth” in this case refers to the Divine.
In Kundalini yoga, sat nam is used as a greeting and as a closing salutation, as well as a mantra during kriyas and meditation. It is believed that chanting sat nam internalizes the meaning of the mantra and awakens the yogi's soul. The root word nam is also used in the word namaste, a respectful greeting said when giving a namaskar, usually used at the end of a yoga class.