Definition - What does Sat mean?
Sat is a Sanskrit word used in yoga, translated as “the true essence” or “that which is unchangeable.” It can be used to refer to an entity, species or the state of existence. In its most philosophical sense, sat, therefore, means “the ultimate reality” or Brahman.
In Indian writings, sat is commonly used as a prefix for other words, and it generally implies that which is true, real and essential or that which is good and virtuous.
Yogapedia explains Sat
Sat is part of the the important seed mantra used in Kundalini yoga practice, especially sat nam. This mantra combines the meaning of sat as “truth” with nam, which in this context, refers to “identity.” As such, the whole mantra is said to symbolize the truth of the soul.
Because the meaning of sat as “truth” is somewhat intangible and etheric, it is thought to have a vibration as a mantra that reaches upward, through the sahasrara (crown) chakra. When chanted alongside nam, which has a more grounding quality, it is said that the practitioner will feel the flow of energy from the spiritual to the the material. According to Kundalini yoga teachings, this will awaken the soul and balance the five elements, or tattvas.