Ugra tap means fierce or intense austerity. In Jainism, "ugra" = fierce/strong, and "tap" = penance or austerity. So "ugra tap" refers to very strict, severe self-discipline and penance practiced by a Jain ascetic to burn karma and progress on the path to liberation. It denotes a level of austerity greater than ordinary tapas, often associated with extreme fasting, long days of penance, and rigorous disciplines.

Note: Different Jain traditions may use or describe such terms with slight nuance, but the core idea is consistently about intense, uncompromising self-discipline aimed at spiritual purification.