Saṃnyāsa is the formal renunciation of worldly life, the last of the four stages, though many have taken it directly. The renouncer gives up family, property and the sacred fire and wanders, living on alms, devoted to liberation. The Gītā reinterprets renunciation as giving up attachment to the fruits of action rather than action itself.
Saṃnyāsa
Renunciation: the life of the wandering renouncer who has given up home, property and ritual.
Also: Sannyasa, sannyasin