Definition - What does Sadashiva mean?
Sadashiva is one of the forms of Shiva, which, by some, is considered the highest form. He is usually depicted with five faces, representing the five elements and five powers of Shiva, and his 10 arms and hands.
The Sanskrit prefix, sada, translates as "always" and "forever." As such, Sadashiva is perceived as eternally pure and auspicious.
Yogapedia explains Sadashiva
If sada translates to "always" and Shiva to "auspicious," Sadashiva is "the one who is always happy, loving and auspicious." In yoga, it is believed that one can find Sadashiva deep within oneself.
While the whole world is changing, the body, mind and energies change, but deep inside Sadashiva remains the same. Although challenges may arise on the external level, Sadashiva exists within one's core and even a suffering human being can find happiness from deep within.