Bhadra Tap, also written as Bhadratap, is a Jain austerity (tap) observed for self-purification, karma shedding, and spiritual upliftment. It is also associated with the holy Bhadrapada month. ( jainknowledge.com)

In simple words, it is a religious penance practice done with discipline, devotion, and restraint in Jain Dharma. ( jainknowledge.com)