Definition - What does Buddhahood mean?
In Buddhism, Buddhahood is considered a state of absolute enlightenment attained by a boddhisatva (awakened one). Some schools described it as the universal possession of total knowledge and wisdom.
Buddhahood is the highest of the 10 realms of Buddhist practice. Achieving this is the ultimate goal of a Buddhist practitioner. In order to reach it, they must cultivate a peaceful, compassionate and generous mind in their daily lives.
Yogapedia explains Buddhahood
The Buddha stated that all living beings can attain Buddhahood and encouraged his disciples to aspire to do so. He described the state of Buddhahood with four attributes: true Self, eternity, purity and happiness.
There are many opinions on how to achieve Budhahood, depending on the Buddhist school and it's teachings. However, all schools and traditions of Buddhism agree that Buddhahood involves purifying the mind of desire, aversion and ignorance. Buddhists practice meditation to free themselves from the disturbances and fluctuations of the mind and to realize their true self. There are other practices to cultivate virtue and purify the mind, such as mantra recitation, study of Buddhist sutras and many others that are similar to those taught in yogic traditions. For example, both Buddhism and yoga teach that compassion is part of the path to spiritual liberation.