Definition - What does Gum mean?
Gum is the bija, or "seed" syllable, mantra that represents the energy of the Hindu god, Ganesh. He is the remover of obstacles who brings success, but he is also the god of beginnings and is associated with arts and sciences, knowledge and wisdom.
In general, chanting a bija mantra focuses concentration on one purpose and/or stills the mind. Such mantras are typically chanted as the yogi relaxes in a cross-legged seated position or while lying down.
Yogapedia explains Gum
Ganesh is a powerful and revered deity who is the son of Shiva and Parvati. He is recognizable by his elephant head on a human body. While his bija mantra, Gum, can be chanted singly and repeatedly to enter a deep state of meditation, it can also be included in a longer mantra. One of the most common is:
“Om gum Ganapatayei namaha.” It is typically translated from Sanskrit as “Salutations to the remover of obstacles.”
Whether alone or as part of another mantra, chanted silently or aloud, Gum is believed to have the power to aid the yogi in his/her spiritual progression.